It was one of the first sitcoms to focus on an unmarried woman who was not a domestic or living with her parents, a forerunner of The Mary Tyler Moore Show.

At the end of the 1969–1970 season, That Girl was still doing moderately well in the ratings, but after four years Thomas had grown tired of the series and wanted to move on.

[2] According to Marlo Thomas, she was approached by ABC executive Edgar Scherick, who saw her in a screen test for a failed pilot, but still wanted to feature her in a project.

Bessell's character was Don Blue Sky, Ann's talent agent who was part Cherokee, and Harold Gould and Penny Santon played her parents.

By the time the series aired on ABC, Thomas and Bessell were the only actors to receive top billing.

[11] The pilot episode centered on Ann's attempt to adopt a stage name based on her agent's suggestion.

After her use of "Marie Brewster" (the names of her family and hometown combined) was met with disapproval from her parents, she decided to not make the change in the end.

[12] It has since been added to the series' broadcast syndication package; it led off a New Year's Day marathon on MeTV at the start of 2012.

On January 1, 2012, That Girl reruns returned to national television on MeTV with episodes shown on weekday mornings and Sunday afternoons until September 1, 2013.

[16] In 1973, Rankin/Bass produced That Girl in Wonderland, an animated television special in which Marlo Thomas reprised the role of Ann.

[17] The special also featured the voices of Patricia Bright, Dick Hehmeyer, Rhoda Mann, and Ted Schwartz.

They appeared as a series of T-shirts, then as a Saturday Night Live skit featuring Danitra Vance in an African American remake "That Black Girl",[19] and as a sequence on episodes of Animaniacs,[20] The Simpsons,[21] Family Guy, Clarissa Explains It All, Arthur, Friends[a] and Roseanne.