Can my employer keep my passport in Saudi Arabia?

No. It is illegal for your employer to keep your passport, Iqama card or medical insurance card. The passport belongs to you. If your employer holds it, first ask for it back in writing and keep the message. If they refuse, file a labour-violation report through the MHRSD portal, which is free. You can also call the Ministry on 19911. Passport retention is treated as a violation with a fine on the employer. If your case also involves violence, confinement or a criminal threat, contact the police on 999 and your embassy at once.