The first season of the television series Ally McBeal began airing in the United States on September 8, 1997, concluded on May 18, 1998, and consisted of 23 episodes. It tells the story of Ally McBeal, a young lawyer who found herself without a job after being sexually harassed by her boss, only to end up employed by her friend from college, Richard Fish, to work in the firm he created with his friend John Cage, named "Cage & Fish."

The second season of the television series Ally McBeal commenced airing in the United States on September 14, 1998, concluded on May 24, 1999, and consisted of 23 episodes. On March 22, 1999, Fox aired a special titled Life and Trials of Ally McBeal in which Bill Maher interviewed the cast after nearly finishing two seasons of the show. The special was produced by a different company. The entire season originally aired Mondays at 9pm, just like the season before.

The third season of the television series Ally McBeal commenced airing in the United States on October 25, 1999, concluded on May 22, 2000, and consisted of 21 episodes. The entire season originally aired Mondays at 9pm, just like the seasons before. A month before the premiere of the season, Fox began airing Ally, a half-hour show that consisted of re-edited scenes from the first two seasons and previously unseen footage, with the intention of making it a sitcom. 13 episodes of the show were shot, but only 10 were broadcast.

The fourth season of the television series Ally McBeal commenced airing in the United States on October 12, 2000, concluded on May 21, 2001, and consisted of 23 episodes. The entire season originally aired Mondays at 9pm, just like the seasons before. The fourth season had an average rating of 12.0 million viewers in the United States and was ranked #40 on the complete ranking sheet of all the year's shows. This was the third highest rated season of Ally McBeal.

The fifth and final season of the television series Ally McBeal commenced airing in the United States on October 29, 2001, concluded on May 20, 2002, and consisted of 22 episodes. The entire season originally aired Mondays at 9pm, just like the seasons before. The fifth season had an average rating of 9.4 million viewers in the United States and was ranked #65 on the complete ranking sheet of all the year's shows. In addition to being the lowest-rated season of Ally McBeal and the grounds for the show's cancellation on April 18, 2002, it was also the only season of the show that failed to win any Emmy or Golden Globe awards.