Ross Geller is one of the six main characters of the NBC sitcom Friends, portrayed by David Schwimmer. Ross is considered by many to be the most intelligent member of the group and is noted for his goofy but lovable demeanor. His relationship with Rachel Green was included in TV Guide's list of the best TV couples of all time, as well as Entertainment Weekly's "30 Best 'Will They/Won't They?' TV Couples". Kevin Bright, who was one of the executive producers of the show, had worked with Schwimmer before, so the writers were already developing Ross's character in Schwimmer's voice. Hence, Schwimmer was the first person to be cast on the show.

Ross is a paleontologist and has a Ph.D. His romantic feelings toward Rachel Green (Jennifer Aniston), which began as a high-school infatuation, are an ongoing theme of his narrative arc. Likewise, their on-again, off-again romantic relationship is a nearly constant theme of Friends.

Raised on Long Island, Ross is the elder brother of Monica Geller (Courteney Cox), and son of Jack (Elliott Gould) and Judy Geller (Christina Pickles). Ross and Monica are Jewish and see themselves as at least cultural Jews, with Ross taking a more active role in wanting to teach his son, Ben (Cole Sprouse), about the faith. Ross gets divorced and is newly single in the first episode because his wife, Carol (Jane Sibbett), has realized she's a lesbian. Later in the series, he dates Rachel, but they split up when he sleeps with another woman the night they decide their relationship is "on a break". After his relationship with Rachel ends, Ross marries Emily Waltham (Helen Baxendale), the niece of Rachel's boss. However, because Ross says "I, Ross, take thee, Rachel" instead of Emily during the nuptials, the marriage doesn't last long. In season 5, Ross and Rachel drunkenly marry in Las Vegas, and ultimately that marriage results in a divorce as well; however, they confess that if they ever got married properly it would be the one that lasted. Throughout the series, Ross gets divorced three times. In the first episode of Joey, the spin-off series, it is hinted that Ross and Rachel may have gotten married again, as Joey Tribbiani (Matt LeBlanc) tells his sister Gina (Drea de Matteo) that all of his friends are married.

A running theme in Ross's narrative is his competition with Monica, manifested through wrestling and paranoia.^{[citation needed]} As children, they took part in a family football game for the "Geller Cup" every Thanksgiving. This tradition ended in its sixth year after Monica "accidentally" broke Ross's nose. The siblings came up with a dance in primary school called "The Routine", which they performed as adults at Dick Clark's New Year's Rockin' Eve in a New Year's Eve TV broadcast. When they were children, Monica felt that their parents favored Ross, but as they grew up, she actually liked Ross as a person and loved him more than simply out of a sense of family obligation. As adults, they became close, though the competition between them was still visible, as seen in the season three episode, "The One with the Football".

Ross often comes into conflict with Phoebe Buffay (Lisa Kudrow). His rationality and Phoebe's eccentricity lead to conflict over evolution, gravity, and whether Phoebe's mother was reincarnated as a cat. It is also revealed that Phoebe once mugged Ross (stealing a copy of the comic book Science Boy that Ross had created) when they were teenagers. The two are roommates for a few weeks when a fire forces Phoebe to move out of her apartment. She first moves into Chandler Bing (Matthew Perry) and Monica's apartment but then decides she wants to give the newly engaged couple some privacy, so she moves in with Ross. In a "flashback" episode, they are alone at a bar and start kissing, but the moment quickly passes when Ross keeps bumping his head. Phoebe also helps Ross on numerous occasions, ultimately making him realize that he loves Rachel and they are meant to be together.

Since college, Ross's best friend has been Chandler Bing. In college, they were in a band called Way/No Way, and Ross blamed Chandler when he was caught smoking marijuana. They become brothers-in-law after Chandler married Monica. Though they are best friends, at times Chandler gets annoyed with Ross's geeky behavior.

Ross is friends with Rachel Green, whom he has had a crush on since high school. Rachel viewed Ross as ‘Monica’s geeky older brother’ during high school. During the first episode of the series, when they meet after years apart, he rediscovers his feelings for her. They become close and have an on-and-off romantic relationship through the series. In the final season of the show, Rachel tells him that he means more to her than any other member of their group.

Ross is also close friends with Joey Tribbiani and helps him with auditions. He kisses Joey once in order to help him practice a role as a gay man, only to find out that Joey had already done the audition and didn't get the part. Joey and Ross also briefly try to cut Chandler out of their friend group after Chandler ignores them. They once fall asleep together on the couch after watching Die Hard. Toward the end of the series, however, Ross and Joey become closer friends, often hanging out together after Chandler gets married.^{[citation needed]}