Diane Kingson, who grew up in Yemen, had told the court how Ambassador Fahd al-Mashiri repeatedly tried to have sex with her.
When she refused, he turned his attention to her 19-year-old daughter.
She also told the court that another senior diplomat had pressured her to organize group sex parties and travel with him to Cuba on holiday.
The court found that Qatari diplomats viewed Kingson as "willing to have sex with male colleagues" because she was not a Muslim.
The Labor Court in central London concluded that Kingson had reached the brink of suicide because of her ordeal, which exposed her to humiliation and sexual pressure.