* Janice Hosenstein: A loud, nasally-voiced woman who is known for her "Oh. My. God!" catchphrase. She dates Chandler on and off throughout the series.
* Gunther: The barista at Central Perk who is secretly in love with Rachel.
* Estelle Leonard: Joey's agent who is known for her tough-as-nails attitude.
* Carol Willick: Ross's ex-wife and the mother of their son, Ben. She is a lesbian and is in a relationship with Susan Bunch.
* Susan Bunch: Carol's partner and Ben's other mother. She is a kind and compassionate woman who works as a massage therapist.
* Ben Geller-Willick: Ross and Carol's son. He is a precocious and intelligent child who loves dinosaurs.
* Emma Geller-Green: Ross and Rachel's daughter. She is a sweet and innocent child who brings great joy to her parents.
* Jack and Judy Geller: Ross and Monica's parents. They are a loving and supportive couple who are always there for their children.
* Phoebe's twin sister, Ursula: A waitress and actress who is the polar opposite of Phoebe. She is selfish, manipulative, and often mean-spirited.
* Mike Hannigan: Phoebe's boyfriend and eventual husband. He is a kind, funny, and supportive man who loves Phoebe unconditionally.
* David Schwimmer: Ross Geller
* Matt LeBlanc: Joey Tribbiani
* Matthew Perry: Chandler Bing
* Courteney Cox: Monica Geller
* Jennifer Aniston: Rachel Green
* Lisa Kudrow: Phoebe Buffay