In 1980, Winningham won the Emmy Award for Best Supporting Actress In A Miniseries Or A Movie for her role in the critically acclaimed Amber Waves, a TV movie about a rough farmer (Dennis Weaver) who finds he is dying of cancer. In that year she also broke into film in One Trick Pony, starring Paul Simon. In 1983, Winningham was nominated for a Canadian Genie Award for her work in the futuristic 1981 drama Threshold, and appeared in the 1983 epic miniseries The Thorn Birds. In 1984 she starred as Helen Keller in Helen Keller: The Miracle Continues.

Winningham achieved greater fame in 1985's St. Elmo's Fire as one of the original "brat pack" alumni. Despite the film's success, she refused to cash in on her teen idol status, and returned to television in the Hallmark Hall of Fame movie, Love Is Never Silent, for which she received an Emmy nomination. Winningham finished the 80s with two Hollywood films, the nuclear disaster drama Miracle Mile (198, for which she received an Independent Spirit Award nomination in 1989, and the Tom Hanks vehicle Turner & Hooch in 1989. In 1988 Winningham also starred in the Los Angeles stage production of Hurlyburly with Sean Penn and Danny Aiello. fake by lagrange5