Wells attended Stephens College in Columbia, Missouri. She later transferred to the University of Washington in Seattle, where she graduated in 1960 with a Degree in Theatre and was a member of Alpha Chi Omega sorority.

In 1959, Dawn Wells won the title of "Miss Nevada" and represented her state in the 1960 Miss America pageant. After moving to Hollywood she began appearing in guest roles in such television series as 77 Sunset Strip, Maverick, and Bonanza before winning the role of Mary Ann.

She starred with Michael Dante in the 1975 independent movie, "Winterhawk" as a Western settler kidnapped by a Native-American chief.

In the 1990s, she spoofed her character on a commercial for 1-800-COLLECT. She has also reprised her role as "Mary Ann" in the various Gilligan's Island reunion specials, and on an episode of ALF.

Today, she runs a successful business making special clothing for people with limited mobility. Still active in local theater across the country, Wells also runs an ongoing actor's workshop from her ranch in Driggs, Idaho. Further, Wells is also a dedicated alumna of Stephens College in Columbia, Missouri, having been instrumental in fundraising efforts for the college for many years.

In April 2005, according to Forbes Collector, Wells personally consigned for sale, via an auction house in Beverly Hills called Profiles in History, her original gingham blouse and shorts ensemble from her signature role. The winning bid for the Mary Ann Summers outfit from Gilligan's Island was $20,700. Polls taken at colleges periodically pop up on the Internet showing that by lopsided odds, men prefer "Mary Ann" to the more glamorous "Ginger" character on the island.