Women often migrate within developing countries for different reasons than men and female migrants tend to be very differently distributed across economic sectors as compared to male migrants. This paper provides some of the first evidence on the labour market impacts of female internal migration, examining effects in both the productive and household sectors. The paper merges large sample migration data from South African censuses with detailed labour force survey data, and exploits substantial time-variation in female migrant inflows into over 200 districts. To identify the causal effects of migration on labour market outcomes, the author makes use of the unique history of South Africa to construct a plausibly exogenous shift-share instrument for female migrant concentration based on earlier male migration flows from reserves during the Apartheid period. The author firstly finds that this migration increases the employment and hours worked of high-skilled women (but not men). The paper demonstrates that this effect is driven by substitution in household work as many female migrants find work as domestic helpers. Furthermore, female migration leads to a (short-term) reduction in the employment of low-skilled female non-migrants, suggesting an increase in competition at the bottom of the economic ladder.