She was a freelance host at WNET-TV in New York, then staff. She worked for the Associated Press and WCBS-TV. In 1977, she was the guest host of the MacNeil–Lehrer Report while Robert MacNeil was absent, and has hosted a number of PBS specials. In 1983–85 she was a reporter/editor for Condé Nast.
She received a 1994 George Foster Peabody Award along with producer Alan B. Goldberg for the "Hunger Inside" a 20/20 documentary about extreme anorexia.
Sherr is an unabashed feminist. She has twice (in 1989 and 1992) been the recipient of the Planned Parenthood Federation of America's (PPFA) Margaret Sanger Award (known as the "Maggie"), which is awarded to journalists for "exceptional coverage of reproductive rights and health care issues" in the view of PPFA. She also hosted PPFA's Maggie Awards luncheon in 2010.
Sherr has rejected calls for a "new feminism", remarking, "What's wrong with the old feminism?" She has criticized Sarah Palin for calling herself a feminist, demanding, "What, exactly, has she done legislatively for other women? What paths has she forged?"
Sherr was featured in the Jewish Women's Archive web feature, Jewish Women and the Feminist Revolution.
She is the author of Outside the Box: A Memoir, published in September 2006, which chronicles her life on and off TV, including her husband's death from cancer as well as her own battle with colon cancer.
- Susan B. Anthony Slept Here: A Guide to American Women's Landmarks (co-author, 1994)
- Failure Is Impossible: Susan B. Anthony in Her Own Words (1996)
- Tall Blondes: A Book About Giraffes (1997)
- America the Beautiful: The Stirring True Story Behind Our Nation's Favorite Song (2001).
- Sally Ride: America's First Woman in Space (2014)
- ABC News 20/20 profile
- Lynn Sherr at the Internet Movie Database
- The Giraffe Conservation Foundation  where Lynn Sherr is a Founding Patron.
- Booknotes interview with Sherr on Failure is Impossible: Susan B. Anthony in Her Own Words, March 5, 1995.