The show's production team were hoping to include an appearance from Clinton in the upcoming 100th episode, according to the New York Post.
An insider alleged: "They hoped he would appear next week to shoot the episode. They included him on the call list, but it didn't happen."
Series creator and star Tina Fey apparently wrote directly to Clinton advisor Doug Bang to discuss an appearance. However, a representative for Clinton claimed that the former president was not made aware of the request.
"The request was made and immediately denied without asking him," they said.
30 Rock airs on Thursdays at 10/9c on NBC. The show's 100th episode is expected to air on April 20.