Though Tess is unquestionably the sole lead character, actress Melanie Griffith is billed third in the credits, after Harrison Ford and Sigourney Weaver who have supporting roles in the movie. Griffith had received critical acclaim for earlier performances in Body Double (1984) and Something Wild (1986), but those films barely made a dent at the box office and she was still largely unknown when Working Girl (1988) was made in 1988. 20th Century Fox wanted a big name actress to play Tess, but Mike Nichols pushed for Griffith until the studio ultimately gave in.
According to casting director Juliet Taylor, "Mike and I had already kind of fallen for Alec Baldwin and wanted him to play Jack, but the studio was catatonic about that. They did not want two unknowns in the leads." Producer Douglas Wick recalls "So, Mike had to call Alec and say, 'Look, I'm really sorry. The circumstances have changed. Would you do this other part?' Alec understood and was so lovely about it. He came in and really nailed that character. It was an awkward adjustment."
Sigourney Weaver and Melanie Griffith followed several female executives and secretaries on their hectic daily schedules in New York City and sat in during meetings to get a better idea of the industry from the female perspective.
Carly Simon's "Let the River Run" was the first of only two songs to win an Oscar, Golden Globe and Grammy while being written, composed and performed by a single artist. The other one is Bruce Springsteen's "Streets of Philadelphia" from Philadelphia (1993).