She suffered the stroke last night at her home in LA, according to a statement on her official Facebook page, said The Hollywood Reporter.
"She is currently undergoing testing to determine how severe the stroke was. Please keep her in your thoughts," said her representative.
Her "Star Trek" co-star George Takei has expressed his sympathy and support on Twitter.
"We understand #NichelleNichols has been rushed to the hospital. We don't have any diagnosis on her condition but our thoughts are with her," he tweeted.