The Waitress (Mary Elizabeth Ellis) is the most frequently recurring character outside of The Gang. She works at a coffee shop not far from Paddy's, and is introduced in the first episode, "The Gang Gets Racist," as the object of Charlie's affections. The Waitress has absolutely no interest in Charlie but harbors an unrequited crush on Dennis, who slept with her in the episode "Charlie Has Cancer". She did spend the night with Charlie while they were both at the Jersey Shore but only did so because she was high on Ecstasy, and in the morning she was sickened and ran away from Charlie after accusing him of raping her. However, Charlie wasn't upset by her reaction and was happy he got to spend any time with her at all. Charlie goes to great lengths to woo her, while she goes to great lengths to attract Dennis' attention. In attempts to make Dennis jealous, she "banged" Frank in the episode "Mac Bangs Dennis' Mom" and went grinding on a homeless man in the episode "The Gang Dances Their Asses Off." Frequently, her infatuation with Dennis causes her to make decisions against her better moral judgment. Also because of her obsession with Dennis, she is often the victim of The Gang's manipulative schemes. She is a recovering alcoholic, a fact referenced first in "The Gang Gives Back," when she becomes Charlie's Alcoholics Anonymous sponsor, and referenced again in "Who Pooped the Bed" and "The Waitress Gets Married."
As a running gag, none of the characters seem to know her real name; she is simply referred to as "The Waitress," and directly as "Waitress." It was hinted Charlie may know her name in "The Gang Sells Out" when he chides her for liking Dennis when he doesn't even know her real name. The only clues to her real name are that it does not start with "W" and is not "Beautiful"; the name Dennis gave to her when he was accused of not knowing what it was. In "The Waitress Is Getting Married," it is revealed that she went to high school with the gang, and she and Sweet Dee both dated the same guy in high school. She attends the high school reunion with the gang, where her name tag is missing, (further implying her status as 'easily forgettable', a theme in that episode), preventing her name from being revealed. Many fans assumed her name was Nikki Potnick when Frank shows up with a stolen name tag with that name. However, Glenn Howerton specified on Twitter that this is not the case.
Mary Elizabeth Ellis is Charlie Day's real-life spouse.
Artemis (Artemis Pebdani) is one of the more frequently recurring secondary characters, introduced in "Charlie Gets Cancer" as Sweet Dee's friend from her acting classes who acts out a scene from Coyote Ugly (a film that featured actress Kaitlin Olson in a small part). Artemis is overly serious about her craft and displays bizarre habits and outbursts. She is very open about her sexuality and often offers to perform in the nude, even when it is unnecessary. Recently she was involved in a sexual relationship with Frank and the two shared a food fetish. She likes having sex with bacon bits in her hair because it makes her feel like a cobb salad. She and Frank once had sex in a dumpster behind Wendy's, where she did something with a roll. She has openly proclaimed that she has a "bleached asshole".
Matthew "Cricket" Mara
Father Matthew "Rickety Cricket" Mara (David Hornsby), usually referred to as "Cricket","Crick" or "Street Rat" is a Roman Catholic priest who becomes defrocked, destitute, abducted, assaulted (both non-sexually and sexually), threatened, hunted, severely injured and addicted to cocaine all directly or indirectly resulting from the influence or action of his former high school classmates: Deandra, Dennis, Charlie and Mac. As a boy he suffered from a medical condition that required the use of very conspicuous complex leg braces which inspired the pejorative nickname "Rickety Cricket". He first appears in "The Gang Exploits a Miracle" where it is revealed that he has continued to harbor a highschool crush on Deandra (who at the time used an elaborate semi-permanant aluminum medical back brace earning her the moniker: "The Aluminum Monster"). He admits he was convinced to eat horse feces for a chance to kiss Dee, which she refused since, as she says, "his breath smelled like shit". Mac and Dennis have been teabagging Cricket at every opportunity since high school. Dennis claims that he has a shoebox full of pictures of him and Mac doing this, and pictures are surfacing on the Internet. One recurring theme in the series is Cricket's downward spiral; due to his involvement with the Gang he leaves the priesthood, supports himself by grifting or panhandling, becomes addicted to crack cocaine, has his legs broken by members of the Philadelphia Mafia, has his throat severely injured by Frank in a wrestling match, and is hunted by Mac and Dennis for sport. He has since carried a vendetta against The Gang and attempts to get his revenge in various episodes, but consistently fails to do so. He shows up in "Mac's Big Break", when he appears on Dennis and Sweet Dee's inaugural podcast, remarking about his life as a homeless person. He also shows up in "Dee Gives Birth" because Frank was trying "to cast a wider net" in finding out the identity of Dee's baby's father and he considered Rickety Cricket to be "the wildcard". He shows up at his High School claiming to have returned to being a priest but actually uses the opportunity to steal jewelry from the other students. The other students mock him when it is discovered he has ring worm.
Brothers Liam (Jimmi Simpson) and Ryan McPoyle (Nate Mooney) are creepy former elementary-school classmates of Mac and Charlie. They are introduced in "Charlie Got Molested" when they falsely accuse a former teacher of pedophilia and Charlie and the rest of the gang foil their plan and turn them in to the police, which sparks the McPoyles' antipathy toward the Paddy's Pub gang. Liam and Ryan have an incestuous relationship with each other and their deaf-mute sister Margaret (Thesy Surface). As seen in "The Gang Gets Invincible", they have at least 14 other siblings and family members, who all sport the McPoyle unibrows, acne, and eczema. The most notable relative is "Doyle McPoyle" (Bob Rusch), an aspiring football player who lost his chance to play for the Philadelphia Eagles when a hallucinating Frank accidentally shot him in the leg. Ryan and Liam avenge this in the episode "The Gang Gets Held Hostage" by faking a raid on the bar. Ryan seems to have an strange obsession with Pledge furniture cleaner and all The McPoyles seem to only drink milk and prefer warm, clammy conditions, which explains their constant sweaty appearance.
Carmen (Brittany Daniel) is a male-to-female transsexual who was dating Mac. She first appears in the season 1 episode "Charlie Has Cancer", then reappears in the season 3 episode "Mac Is a Serial Killer". She is attractive but displays an obvious bulge in her pants. She keeps Mac interested in her with promises of undergoing sexual reassignment surgery and with constant flattery of Mac's physique. In "Mac Fights Gay Marriage", she has completely removed her penis, and has gotten married to Nick, much to Mac's chagrin. In "Dee Gives Birth" it is revealed that Carmen is the father of Dee's baby (she had her sperm frozen before she had her penis removed) and that they used an anonymous egg donor and Dee was merely a surrogate. Dee gave the baby to Carmen and her husband Nick to raise. In the unaired pilot Carmen is portrayed by Morena Baccarin.
Nick (Windell Middlebrooks) is Carmen's portly African-American husband. Mac is initially annoyed that Carmen had moved on to Nick instead of calling him after she had her penis removed. Mac does not agree with gay marriage and quotes the Bible verse Romans 1:27 to Nick, to which Nick responds with the Bible quote Exodus 21:20 endorsing slavery. Nick later appears in "Dee Gives Birth" where it is revealed that Dee is a surrogate for the couple since Nick cannot have kids but Carmen had frozen her sperm before her operation.
Ernie (David Zdunich) is the "Barfly" who is commonly seen in the background in the bar. He is in every single episode that is shot in the bar, but he is noticed in the episode "Paddy's Pub: The Worst Bar in Philadelphia." handing over the paper to the "gang" for them to see the journalist's article. David Zdunich died in 2009. The season five episode "Paddy's Pub: Home Of The Original Kitten Mittens" was in his memory.
The Lawyer (Brian Unger) is first seen in "Dennis and Dee's Mom Is Dead" where The Gang mistake him for having personal involvement as the executor of Barbara Reynolds' will. He returns in Season 5, eager to personally stop Frank—he represents a family that Frank is trying to force out of their house. After Charlie makes an attempt to prove that he's more legally apt than the actual lawyer, he challenges him to a duel; the lawyer immediately accepts, claiming to have a loaded gun in his office desk. He also appears again in "Paddy’s Pub: Home of the Original Kitten Mittens" when The Gang goes to him to get patents for products that they have created. He later tricks them into signing a document that grants him all the profits from the products that is also a restraining order against The Gang. He makes hundreds of copies after learning of Mac's tendency to eat such documents. He next appears in "Dennis Gets Divorced" where he represents Dennis's wife Maureen Ponderosa pro bono in their divorce.
Ben Smith (Travis Schuldt) is first introduced in "The Gang Wrestles for the Troops" as Dee's online chat buddy "soldier of fortune". He served as an American soldier in Iraq. He is mistaken as a handicapped person while getting off a bus from the airport in a wheelchair. Dee does not want to date a handicapped person so she decides to pretend that he was talking to Artemis over the internet, but soon discovers he isn't handicapped, he just twisted his knee getting off a plane in Germany. Ben is seen again in the episode "The D.E.N.N.I.S system" as Dee's boyfriend. He dumps her, calling her a "mean person" and goes for a pharmacist that dumped Dennis after the latter "Dennis-ed" her. Travis' character recurs again in season six with the episode "Mac's Big Break." Ben is seen chiefly wearing the jean shorts Frank purchased for him as a welcome-home gift. He appears again in "Dee Gives birth" as one of Dee's baby's potential fathers. He is again seen wearing the jean shorts.
Brad Fisher (Nick Wechsler) is first introduced as the Waitress' fiancee in the season 5 episode "The Waitress Is Getting Married". Brad dated both Dee and the Waitress in High School but both dumped him because of his acne. He rekindles both relationships in a plot to humiliate them. Charlie gives Brad a wedding gift of a box full of hornets. Brad returns in the season 7 episode "The High School Reunion" where his face is scarred from the hornet stings.
Ingrid "Fatty McGoo" Nelson
Ingrid Nelson aka Fatty McGoo (Judy Greer) was a high school friend of Sweet Dee's who appeared in the season 3 episode "The Aluminum Monster Vs. Fatty McGoo". In High School Dee wore a back brace and was dubbed the Aluminum Monster while Ingrid was morbidly obese and was given the name Fatty McGoo. Dee would always build herself and put Ingrid down. Ingrid grew up to be a rich and successful fashion designer. Dee feeling threatened by Ingrid's success tried to get the Gang's help in destroying Ingrid while Dennis tried to sell his dress design to her even going so far as to wear it himself. Ingrid later returns in the season 7 finale "The High School Reunion: The Gang Gets Revenge".
Uncle Jack Kelly (Andrew Friedman) is Charlie's uncle (the brother of Charlie's mother Bonnie). He first appeared in the season 1 finale "Charlie Got Molested" wherein Charlie's family gives him an intervention to get him to admit he had been molested by his elementary school teacher (this belief was fostered by the scam the McPoyles were running to extort money from the school system). Uncle Jack appears again in the season 5 episode "The Great Recession." When Charlie tries to move back in with his mother after Frank kicks him out of their apartment, she reveals that she sublet Charlie's room to Uncle Jack to earn extra money. Jack insists they share the room and spend time wrestling there. In the season 6 episode "Dennis Gets Divorced," Charlie and Frank call in Jack, who is revealed to be a lawyer, to handle their divorce. Later, Dennis and Mac use him to try to get their apartment back from Dennis' ex-wife, only to find that she hired The Lawyer. Jack proves to be incompetent, getting the apartment back in exchange for Dennis taking his wife's $90,000 debt. It is heavily implied that Uncle Jack is a pedophile and wants to have sex with his nephew. Charlie has mentioned how, as a child, he would stay awake at night because Uncle Jack would want to sleep in his bed, and Charlie's lyrics to "Nightman" seem to revolve around a man sneaking into his room at night and raping him.
Gladys (Mae Laborde) is the senior citizen with a penchant for long rambling stories who played the piano during Charlie's play in the season 4 finale "The Nightman Cometh". Dennis pretends she is his grandmother to win back a former girlfriend in "The D.E.N.N.I.S. System". In her many stories she claims she was friends with Calvin Coolidge and that her grandmother was the lesbian lover of Susan B. Anthony.
Kevin Gallagher (Kyle Davis) a potentially retarded rapper who dates Dee in "Sweet Dee Is Dating A Retarded Person". Dennis convinces Dee to dump Kevin because he's retarded only for her to later discover he isn't. He later returns as one of Dee's potential baby's fathers in "Dee Gives Birth".
Rex (TJ Hoban) first appears in "America's Next Top Paddy's Billboard Model Contest" as one of the male models vying for the spot on Paddy's Pub's billboard. Although an early favorite of Frank's eventually Frank himself appears on the billboard. Rex returns in "Dee Gives Birth" where it is revealed he has slept with Dee after she insulted him.
Maureen Ponderosa (Catherine Reitman) is Dennis's high school girlfriend and the sister of Bill Ponderosa. Dennis eventually gets back in touch with Maureen and marries her in "Mac Fights Gay Marriage". She has a dead tooth that makes her breath "smell like she nibbled on little pieces of shit". Dennis gets tired of Maureen fairly quickly and in "Dennis Gets Divorced" she hires the Lawyer as her divorce attorney, ending up in a total demolition of Dennis where he has to assume her tens of thousands of dollars in debt as well as pay her monthly alimony. She later appears in "The High School Reunion" and reveals she's spending her alimony money on a diamond for her dead tooth.
Bill Ponderosa (Lance Barber) first appears in "Mac Fights Gay Marriage" and the follow-up episode "Dennis Gets Divorced" as Dee's high school crush and the brother of Dennis's high school girlfriend Maureen Ponderosa. He has put on a lot of weight since high school. Dee eventually becomes his mistress when Dee thinks he bought her a new car when in fact the car belongs to another of Bill's mistresses. Bill returns to his wife. Bill later returns in "Dee Gives Birth" as one of Dee's potential baby's daddies. Bill reveals that he tells girls he's had a vasectomy so he doesn't have to use a condom. He also displays an affinity for cocaine.
The Korean Busboy (Maxie J. Santillan Jr.) worked at the Korean restaurant that threatened to steal business away from Paddy Pub's in "The Gang Solves The North Korea Situation". Dee sleeps with him to get information about their secret microbrew recipe. He laters returns as one of Dee's potential baby's fathers in "Dee Gives Birth".
Principal Brian McIntyre
Principal Brian McIntyre (Dave Foley) is the high school principal who hires Dee as a substitute teacher and Charlie as a janitor in "The Gang Gets A New Member". He fires both of them in the next episode "Dee Reynolds: Shaping America's Youth" because Dee took her students on a field trip to Paddy's Pub to watch Mac and Dennis's Lethal Weapon 5 movie and because Charlie's mentoring of a student named Richie led to him dressing up in blackface after watching the movie. The principal laments that he probably won't be employed at the school much longer either due to their shenanigans.
Duncan & Z
Duncan (David Gueriera) and Z (Chad Coleman) are Frank's bizarre friends that he met under a bridge. They appear in "Charlie Kelley: King Of The Rats" where Frank wants the gang to invite them to go to the gang's luau. They later appear in "Dee Gives Birth" to provide music for their party/interrogation of Dee's potential baby's daddies.
Peter "Schmitty" Schmidt
Peter Schmidt aka Schmitty (Jason Sudeikis) A former member of the gang back in high school. Mac and Dennis kicked Schmitty out of the gang (and a moving car) to make Charlie happy. Charlie and Schmitty used to be roommates and Charlie always feels upstaged by Schmitty. The gang kicks Charlie out and welcomes Schmitty back in the season 6 episode "The Gang Gets A New Member" but he quickly earns their ire when he upstages Mac and Dennis and is kicked out again. He returns in the Season 7 finale "The High School Reunion: The Gang Gets Revenge" and appears out of nowhere to take the Waitress up on her drunken offer to bang 'the next guy who talks to her', (just seconds before Charlie can utter a word).
The Rum Ham is a anthropomorphized ham soaked in rum that Frank somehow obtains in "The Gang Goes to the Jersey Shore." Mac estimates that it is about 90-proof. Rum Ham accompanied Frank and Mac on their ill-advised inflatable raft ride. While Frank and Mac are passed out Rum Ham somehow ends up in the water, and floats away. Frank is crushed by the loss of his friend, and goes so far as to try to stab Mac yelling "It should have been you!" The ham is later serendipitously recovered by an Italian fisherman, at which point Frank and Mac resume eating it. The remains of the Rum Ham can be seen in the background of "Frank Reynolds' Little Beauties" in Frank and Charlie's apartment.