Few studies have analyzed variation in the motherhood wage penalty by the sex composition of women’s jobs. This study draws on nationally representative data to investigate the motherhood wage penalty for women who work in female-dominated, male-dominated, and integrated jobs. Fixed-effects estimates reveal that women who work in female-dominated jobs pay a larger motherhood wage penalty than women who work in other jobs. This larger penalty is not offset by measurable compensating differentials, such as flexible scheduling or part-time work hours.