Ryan made her screen debut in a small role in the 1983 film Without a Trace. From 1989 to 1993, she starred as Elizabeth Cooper-MacGillis in the NBC sitcom Major Dad opposite Gerald McRaney. She later went to star in the Independent films Love Always (1996), Slaves to the Underground (1997), Taylor's Return (1997), and With or Without You (1998). In 1998, Ryan joined the cast of Fox police drama series, New York Undercover as Det. Nell Delaney, during the show's fourth and final season. She later guest-starred on The Practice, Sex and the City, Law & Order: Special Victims Unit, and Law & Order.
Ryan was born in Manhattan, New York. In 1993, Ryan married actor Jeremy Sisto. They divorced in 2002, after nine years of marriage.
In 2001, Ryan co-starred as Abby Bernstein in the ensemble cast satirical comedy film Wet Hot American Summer. She reprised her role in the Netflix prequel series, Wet Hot American Summer: First Day of Camp in 2015. She also appeared in films Don's Plum (2001), Riding in Cars with Boys (2001), and Brooklyn Lobster (2005). In 1997, she made her directorial debut with the independent short film Three Women of Pain which she also co-wrote.
