Courteney Cox was originally offered the role of Rachel on Friends, but she turned it down because she felt like she related to Monica more.
Jane Krakowski, Tiffani Thiessen, and Téa Leoni auditioned for Rachel too.
Ellen DeGeneres was offered the role of Phoebe on Friends, but she turned it down and Lisa Kudrow was cast.
Kathy Griffin and Jane Lynch also auditioned for Phoebe.
Connie Britton was one of the network's choices to play Olivia Pope, but Shonda Rhimes insisted Olivia should be played by a black woman instead.
Taraji P. Henson was another famous person who went in to read for the role of Olivia Pope.
Rumer Willis was originally pitched to play Serena Van Der Woodsen, but at the time, the casting director wanted to go with a lesser known actress and cast Blake Lively instead.
Ashley Olsen was also pitched to play Blair Waldorf.
Elizabeth Olsen actually auditioned for Daenerys Targaryen, but Emilia Clarke ended up getting cast.
Bob Odenkirk was actually supposed to play Michael Scott on The Office because Steve Carell was already busy with another series.
Steve's series got canceled though, which freed him up to play Michael. Bob also made a cameo later on in the series.
Chris Rock was one of the many famous actors who was in talks to play George Costanza on Seinfeld.
Nathan Lane, Steve Buscemi, and Paul Shaffer were also brought in to audition for George. Danny DeVito was offered the role but turned it down.
Lucy Hale actually auditioned for Hannah Montana when she was 15 and still lived in Tennessee, which was years before Miley Cyrus eventually got cast.
Oliver Hudson was in the final running for Jack Pearson on This Is Us, but by the time he was scheduled to screen test with Mandy Moore, Oliver went on an already-planned fishing trip instead.
Keke Palmer screen tested for the role of Iris on The Flash, but didn't end up getting it because she looked "a little too young" compared to Grant Gustin.
Selma Blair was actually Dawson's Creek creator Kevin Williamson's first choice to play Joey.