There are many potential determinants of women?s labour supply including wages, unearned income, human capital endowments, demographic characteristics and family traits. Fertility behaviour, including the number of children and age of children, is also an important factor in women’s labour supply decisions. Many factors which affect women’s decisions on participating in the labour market and hours of work are also key influences on their decisions on starting a family and having a desired number of children. This thesis provides a comprehensive analysis of the determinants of labour supply and fertility behaviour of Australian women. Using cross-sectional data, labour supply models corrected for sample selection bias, and fertility models examining different aspects of family size, the thesis finds that women’s labour supply decisions are largely influenced by their wages and fertility behaviour. Their decisions on completed fertility, starting a family and having additional children are largely influenced by their actual or potential wages.