It's Always Sunny in Philadelphia character guide

Who is Frank Reynolds in It's Always Sunny in Philadelphia?

Dennis and Dee's legal father, a rich, sleazy former businessman who walks away from respectability, buys into Paddy's Pub, moves in with Charlie, and bankrolls the gang's worst ideas.

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Frank Reynolds's Sitcomdle clue card

The five clues the game shows when Frank Reynolds is the answer or a guess.

Debut
2006
Network
FX
Role
Main
Gender
Male

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Played by
Danny DeVito
First episode
“Charlie Gets Crippled”Season 2, Episode 1, aired June 29, 2006
Role
Main cast
Network
FX
Occupation
Majority owner of Paddy's Pub, ex-businessman
Show run
2005 to presentMoved from FX to FXX in 2013.
Also known as
Franklin Reynolds, Trash Man, Dr. Mantis Toboggan

Frank Reynolds arrives in season two as a wealthy businessman who abandons his marriage and his manners to join his grown children's gang at Paddy's Pub. Played by Danny DeVito, he is the group's money, its eldest member, and usually the one pushing a bad plan even further.

On It's Always Sunny in Philadelphia, Frank Reynolds's story runs through Charlie Kelly (Roommate), Dennis Reynolds (Legal Son), Dee Reynolds (Legal Daughter), Mac (Adopted Son), and The Waitress (Fling).

Frank Reynolds from It's Always Sunny in Philadelphia: Sitcomdle character card

Who is Frank Reynolds?

Frank is the legal father of twins Dennis and Dee, though not their biological one. When he first appears he is a buttoned-up executive in the middle of a divorce from their mother, Barbara. Fed up with the life he has, he decides to give away his money, spend time with his kids, and find out what living without rules feels like.

He soon buys a majority stake in Paddy's Pub and moves into Charlie's grim apartment, where the two share a fold-out bed. Frank keeps plenty of money stashed away, but he prefers to live in squalor, eat out of cans, and treat the gang's schemes as his entertainment.

Personality and comedy

Frank is the show's id with a checkbook. He gambles on anything, is rarely without a loaded revolver, owns a toe knife, and has a history of shady businesses that includes running sweatshops in Vietnam. He calls himself fringe class and seems to enjoy each new low more than the last.

What makes Frank funny is how gleefully he commits. While the younger members of the gang worry about how they look, Frank will strip down, forage naked in the sewer, or eat garbage without a second thought. Underneath it there is a strange tenderness for Charlie, the one person Frank seems to genuinely love.

Key storylines

In "Dennis and Dee Get a New Dad" Frank learns that the twins are not biologically his, which sets off a rivalry with their real father, Bruce Mathis. Over the years he decides to marry a woman from his seedy nightlife in "Frank's Pretty Woman," falls out a window and wakes up convinced it is 2006, and announces his retirement, handing the bar's money decisions to the gang with disastrous results.

For much of the series the show teases that Frank could be Charlie's father, since he once dated Charlie's mother, Bonnie. Season fifteen finally settles it when Charlie meets his real father in Ireland. Frank also legally adopts Mac in "The Gang Goes on Family Fight" so the team can qualify for a game show, and the season seventeen finale makes him the star of a Golden Bachelor finale.

Behind the scenes and legacy

Frank did not exist in the first season. After season one drew small ratings, FX asked the creators to add a recognizable name to help promote the show, and Danny DeVito joined for season two. His arrival is often credited with helping the series survive and find a bigger audience.

DeVito has played Frank for two decades, and the role brought the veteran star a whole new generation of fans. Clips of Frank, from his rants to his alter ego Dr. Mantis Toboggan, are among the most shared moments from the show.

Key Frank Reynolds episodes

  1. “Charlie Gets Crippled”Season 2, Episode 1Frank shows up, leaves his wife and his old life, and moves in with Charlie.
  2. “Dennis and Dee Get a New Dad”Season 2, Episode 10Frank learns the twins are not biologically his, kicking off his feud with Bruce Mathis.
  3. “The Gang Gives Frank an Intervention”Season 5, Episode 4Dee, Dennis, and Charlie stage an intervention over Frank's drinking, and it collapses into a roast and a string of counter-interventions.
  4. “Frank's Pretty Woman”Season 7, Episode 1Frank decides to marry Roxy, a woman from his seedy nightlife, and Dee tries to clean her up.
  5. “Frank Falls Out the Window”Season 11, Episode 2A head injury convinces Frank it is 2006, and the gang tries to use it to fix old mistakes.
  6. “Being Frank”Season 11, Episode 6An entire episode shot from Frank's point of view as he chases a scheme across the city.

Season and episode numbers follow the original broadcast order.

Frank Reynolds: frequently asked questions

Who plays Frank Reynolds in It's Always Sunny in Philadelphia?

Danny DeVito plays Frank Reynolds. He joined the cast in season two in 2006 and has been part of the main cast ever since.

When does Frank join It's Always Sunny?

Frank first appears in "Charlie Gets Crippled," the season two premiere, which aired on June 29, 2006. He is not in season one.

Is Frank Dennis and Dee's real father?

No. Frank is their legal father, but in season two the twins learn their biological father is Bruce Mathis.

Is Frank Charlie's father?

No. The show hinted at it for years, but in season 15 Charlie learns his real father is Shelley Kelly, his Irish pen pal.

Why was Danny DeVito added to It's Always Sunny?

FX wanted a well-known actor to help promote the show after its low-rated first season, and DeVito joined as Frank starting in season two.

Test yourself: Frank Reynolds quiz

5 questions about Frank Reynolds. Think of your answer, then open the reveal to check it.

  1. Question 1

    Which famous actor joined the cast as Frank Reynolds starting in season two?

    1. Joe Pesci
    2. Jeff Garlin
    3. Bob Odenkirk
    4. Danny DeVito
    Show the answer

    Answer: D. Danny DeVito

    FX wanted a bigger name after a low-rated first season, and DeVito arrived in the season two premiere as the twins' father.

    See question 2 in the full quiz

  2. Question 2

    Who turns out to be Dennis and Dee's biological father?

    1. Frank Reynolds
    2. Bruce Mathis
    3. Shelley Kelly
    4. Brad Fisher
    Show the answer

    Answer: B. Bruce Mathis

    In "Dennis and Dee Get a New Dad," Bruce reconnects with the twins through Dee's MySpace page, and Frank does not take the news well.

    See question 9 in the full quiz

  3. Question 3

    What fake doctor alias does Frank love to use?

    1. Dr. Rex Fandango
    2. Dr. Larry Lobster
    3. Dr. Hank Sledge
    4. Dr. Mantis Toboggan
    Show the answer

    Answer: D. Dr. Mantis Toboggan

    Frank creates the Mantis Toboggan persona in "The D.E.N.N.I.S. System" and keeps bringing the good doctor back for later schemes.

    See question 10 in the full quiz

  4. Question 4

    In which episode does Mac come out for good?

    1. Mac Finds His Pride
    2. Mac Day
    3. The Gang Goes to Hell
    4. Hero or Hate Crime?
    Show the answer

    Answer: D. Hero or Hate Crime?

    "Hero or Hate Crime?" starts as an argument over a lottery ticket and a falling piano, and ends with Mac saying who he is for keeps.

    See question 11 in the full quiz

  5. Question 5

    Who does Charlie discover is his biological father during the gang's trip to Ireland?

    1. Frank Reynolds
    2. Bruce Mathis
    3. Mac's father, Luther
    4. His pen pal Shelley
    Show the answer

    Answer: D. His pen pal Shelley

    In "The Gang's Still in Ireland," Charlie finally meets Shelley Kelly, the pen pal he wrote to as a kid, and learns that Shelley is not his brother but his father.

    See question 17 in the full quiz

Take the full It's Always Sunny in Philadelphia quiz (20 questions)

Sources and corrections

Reference pages used for this guide, including character, cast, and episode details.

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