Shelley was a busy actress in the 1980s. After opting to leave Charlie's Angels in 1980, she went full-time into an acting career. She appeared in various stage, movie and TV productions. In 1981, she tackled stage via Jack Heifner's Vanities, then in 1982 Elizabeth Diggs's Close Ties (both taped for HBO's Standing Room Only series). Later that year, she starred in Born Yesterday with the prestigious Pennsylvania Stage Co. She surprised all her critics and detractors with her excellent performances in these plays. On the big screen, she starred with Robert De Niro and Jerry Lewis in Martin Scorsese's 1983 film The King of Comedy, shared the big screen with Michael Moriarty and Sonny Bono in 1984 in Troll, and played opposite Terry O'Quinn and Jill Schoelen in Joseph Ruben's chilling 1987 horror classic The Stepfather - receiving glowing reviews for her performances. On TV, she starred in Trackdown: Finding the Goodbar Killer with George Segal as well as Found Money with comedy legends Dick Van Dyke and Sid Caesar, in 1983. She also had lead parts in the TV series Cutter to Houston (alongside Jim Metzler and Alec Baldwin) and Jack and Mike (with Tom Mason) - in 1983 and 1986 respectively. She closed the decade with John Krizanc's play Tamara in 1989. It was one busy and redeeming decade for the Hollywood star.