The unidentified representative said Doherty was "looking forward" to appearing on the spin-off of the 1990s series, which is to premiere on the CW network Sept. 2, People magazine reported exclusively Saturday.
"Shannen is looking forward to returning to 90210," the representative said.
Doherty will reprise her "90210" character of Brenda Walsh for the new series as Walsh has grown from emotional teenager to visiting drama teacher at a Beverly Hills high school.
Doherty marks the third former star of the popular drama to join the cast of the CW's "90210." Jennie Garth and Tori Spelling also have joined the production.
Garth and Spelling played teenagers Kelly Taylor and Donna Martin respectively on the original series and "90210" Executive Producer Gabe Sachs assured fans all three actresses will not have small parts in the new production.
"They will be in multiple episodes," he said at a press tour Saturday.