Monica E. Geller (born April 22, 1969) is a fictional character on the popular US television sitcom Friends (1994-2004), played by Courteney Cox Arquette.

Monica is the younger sister of Ross Geller. It was revealed over the course of the series that she was an extremely overweight child and weighed up to 255 pounds before losing weight sometime during her freshman year of college after hearing Chandler call her fat. Monica was shown in her earlier "fat" stage in flashback scenes in a few episodes, with Courteney Cox wearing a fat suit. She met Ross' friend Chandler Bing (who suggested that she should become a chef) when he and Ross were in college; Monica and Chandler got together in London during the season 4 finale. They were married in Season 7.

Monica shared her apartment with Phoebe Buffay, who moved out before the series actually began, fearing their relationship would be strained when Monica's neatness became a burden. Monica's new roommate was her friend from Lincoln High School, Rachel Green; in the pilot episode, Rachel left her fiancé Barry Farber at the altar and moved in with Monica. Monica met Joey Tribbiani when he became the new roommate of Chandler, who lived across the hall from Monica.

Monica quickly emerged as the "Mother Hen" of the group; she tended to look after her friends and took on the mammoth task of cooking Thanksgiving dinner for them every year, tailoring the menu to each member's peculiar tastes. Related to her obsessive personality, Monica is also very competitive, especially with brother Ross.

Chandler and Monica

At the end of season 4 Monica began an affair with her close friend Chandler. This happened at Ross's disastrous wedding to Emily in London. Monica was upset after a guest mistook her for Ross's mother and turned to Chandler for comfort (none of this is learned until season 5 though). They kept their relationship secret for a while but eventually Joey found out. The rest of the group then found out one by one, until everybody knew. The two fell in love and eventually moved in together, forcing Rachel to move out. The two married and, in the final episode, watched as their adopted twins, Erica and Jack, were born.

The two almost didn't get engaged because one of Monica's ex-boyfriends, Dr. Richard Burke (played by Tom Selleck) came back into her life. Burke was significantly older than Monica (21 years) but the two fell in love during Season 2. They broke up at the end of that season because Richard was not interested in having children again. A chance meeting with Monica during Season 6 rekindled Richard's passion, and he told her that he was willing to have kids if it meant he could be with her. When Richard discovered that Chandler was going to propose to Monica, he stepped aside so the two of them could be together. They had a romantic wedding aside from Joey's questionable attire (and his marrying them), and discovering that Rachel was pregnant.