The unequal distribution of men and women across occupations is both an historical phenomenon and a reality of today's labour markets. Such occupational sex- segregation is a major factor that produces important differences in individuals' life experiences and is deeply entrenched with other gender inequalities in the work context. This thesis enhances our knowledge on the degree of and patterns in sex- segregation across occupations, explores the mechanisms and processes which produce and perpetuate the division of work tasks by gender, and assesses the consequences of such segregation for important domains of social and economic life. We use large-scale longitudinal survey datasets for Britain and advanced quantitative methods to explore trends in occupational sex-segregation in recent decades and patterns of such segregation in the contemporary British labour market, investigate individual and job-related factors associated with working in occupations with different sex profiles, and estimate the impact of occupational sex-segregation on wages, the gender wage gap, and reported job satisfaction. Our results indicate that occupational sex-segregation in Britain has declined in recent years, but its incidence is still high. Working in. female-dominated occupations is associated with earning lower wages for both men and women and explains a sizeable portion of the gender wage gap. However, the sex-composition of the occupations in which individuals work has smaller and less patterned effects on their reported job satisfaction. Overall, our findings suggest that, despite recent trends towards more equal outcomes for men and women in the labour market, the separation of men and women across lines of work remains important and further research is required to understand its multiple implications.