After Fey studied drama at the University of Virginia, graduating in 1992, she moved to Chicago, getting a job at a residential YMCA by day so she could take classes at The Second City by night. She learned that the key to improvisation was to "focus entirely on your partner. You take what they're giving you and use it to build a scene."

By 1994 she was invited to join the cast of The Second City, where she performed in the Jeff Award-winning revue Paradigm Lost. She is also a veteran of The ImprovOlympic.

With then-head writer Adam McKay's help, Fey became a writer for NBC's Saturday Night Live (SNL) in 1997. In 1999, Fey became SNL's first female head writer, a milestone she downplays[citation needed] by pointing out how few head writers the show has had.

As co-head writer, she won a 2001 Writers Guild of America Award for the show's 25th anniversary special; she and the rest of the writing staff won an Emmy Award in 2002 for their work on the show.

In September 2005, she went on maternity leave, having given birth to a daughter, Alice Zenobia Richmond. Her "Weekend Update" role was covered by Horatio Sanz for several weeks before her return to the show on October 22, 2005, noting:

"I had to get back to work. NBC has me under contract; the baby and I only have a verbal agreement."

Fey confirmed during a July 2006 Tonight Show appearance that she will not be returning to SNL for its 2006-7 season.

Some recurring sketches written by Fey include:

Parodies of Live with Regis and Kelly and The View

The Girl with No Gaydar, cowritten by Rachel Dratch

Boston Teens, cowritten by Dratch

In 2000 Fey and Jimmy Fallon became co-anchors of SNL's Weekend Update, a pairing that ended in May 2004 when Fallon made his last appearance as a cast member. Fallon was replaced with Amy Poehler. Their pair was the first time in history that Weekend Update was anchored by 2 women. Horatio Sanz briefly took Fey's position in October 2005 before Fey returned after giving birth to her first child.

Fey developed a situation comedy, 30 Rock, for NBC's fall 2006 schedule. The show is produced by NBC and Broadway Video, with Lorne Michaels and two former producers of The Tracy Morgan Show, David Miner, who is also her manager at 3 Arts, and Joann Alfano. She also writes and stars in the sitcom, said to be based on her experiences at SNL. The show's title is a reference to 30 Rockefeller Plaza, where SNL is produced.

Similarities between 30 Rock and Studio 60 on the Sunset Strip had led to speculation that only one of the two would be picked up. Alec Baldwin, who played the network executive in the 30 Rock pilot, said "I’d be stunned if NBC picked up both shows. And ours has the tougher task, as a comedy, because if it’s not funny, that’s it." Kevin Reilly, the president of NBC Entertainment, was supportive of Fey, describing it as a "high-class problem":

I just can't imagine the audience would look at both shows, choose one and cancel the other out. In some ways, why is it any different than when there have been three or four cop shows on any schedule, or Scrubs and ER, which are totally very different?

Evidence of the overlapping subject matter between the shows (as well as the conflict between them) is the fact that Aaron Sorkin, the creator of Studio 60, asked Lorne Michaels to allow him to observe SNL for a week, a request Michaels denied. Fey has been said to be taking the high road:

It’s just bad luck for me that in my first attempt at prime time I’m going up against the most powerful writer on television. I was joking that this would be the best pilot ever aired on Trio. And then Trio got cancelled.

In spite of the overlap in subject matter, it was announced on May 15, 2006, that NBC had picked up both shows.

She partnered with fellow cast member Rachel Dratch in the critically acclaimed two-woman show Dratch & Fey at the Upright Citizens Brigade Theater in New York City, the U.S. Comedy Arts Festival in Aspen, Colorado, and the Chicago Improv Festival. Lorne Michaels saw her at one of the performances, which led to her becoming the co-anchor of SNL's Weekend Update.

She also appeared in Martin & Orloff, a surreal comedy which premiered at Austin's SXSW.

Fey wrote the script and co-starred in the 2004 movie Mean Girls. Characters and behaviors in the movie are based on Fey's high school life[citation needed] at Upper Darby High School and on the non-fiction book Queen Bees and Wannabes: Helping Your Daughter Survive Cliques, Gossip, Boyfriends, and Other Realities of Adolescence (ISBN 0-609-60945-9) by Rosalind Wiseman. The cast includes other present and past cast members of SNL including Tim Meadows, Ana Gasteyer, and Amy Poehler.

As of April 2006, Fey is working on a script for a Paramount Pictures film that is said to be based loosely on the true story of a Hasidic rap musician.

Fey was born in Upper Darby, Pennsylvania, a suburb of Philadelphia to a Greek American mother and a father of German and Scottish descent. Her brother, Peter, remembers a drawing she did when she was about seven: it showed people holding hands, walking down the street with wedges of Swiss cheese. The caption read, "What a friend we have in cheeses!"

Fey was exposed to comedy early, saying:

I remember my parents sneaking me in to see Young Frankenstein. We would also watch Saturday Night Live, or Monty Python or old Marx Brothers movies. My dad would let us stay up late to watch The Honeymooners. We were not allowed to watch The Flintstones, though, which my dad hated because it ripped off The Honeymooners. I actually have a very low level of Flintstones knowledge for someone my age.

Fey graduated from Upper Darby High School in 1988. She was inducted into the school's Wall of Fame in 2004.

Tina Fey is married to Jeff Richmond, a composer on SNL. They met before their jobs on SNL and dated for seven years before marrying in a Greek Orthodox ceremony on June 3, 2001[citation needed]. They have a daughter, Alice Zenobia Richmond who was born on September 10, 2005.

Fey also has a facial scar that is sometimes seen on screen. She refuses to talk about it during interviews. However, a Nov. 25, 2001 New York Times article notes that, among varied trademarks: