Katie Puris said in a complaint filed in Manhattan federal court that her 2022 firing was the culmination of a series of incidents where she reported bias and, in one case, sexual harassment to supervisors and human resources.
Puris, who was nearing 50 when she was fired, claims she was subjected to derogatory comments about her age and that ByteDance chairman Zhang Lidong believed women "should remain quiet and humble at all times" and preferred "docility and meekness" in female employees.
She also claims TikTok refused to grant her leave to address medical conditions spurred by the stress and pressure of her job.
TikTok and ByteDance did not immediately respond to requests for comment.
Marjorie Mesidor and Monica Hincken, lawyers for Puris, said in a joint statement that she faced swift retaliation for complaining about discrimination despite being "enormously successful" at her job.
"TikTok’s actions against Ms. Puris are illegal and we look forward to vindicating her rights," they said.
Puris previously worked at Alphabet's Google, Meta's Facebook and major advertising agencies, according to her complaint.
The lawsuit accuses TikTok and ByteDance of violating U.S. and New York state and city laws prohibiting workplace discrimination and retaliation. Puris is seeking unspecified damages for economic losses, pain and suffering, and harm to her reputation and career.
