This monograph examines women and girls' experiences of online harms on social media platforms in Australia. Drawing on qualitative survey responses from forty women aged 18–30 and interviews with fifteen subject matter experts, it explores the types of online harms women and girls encounter on social media and the strategies they employ to navigate and respond to abuse. It foregrounds the experiences of women and girls with marginalised identities, demonstrating how ethnicity, age, sexual orientation and disability compound their exposure to identity-based stereotyping, vilification and targeted harassment. It also explores the regulatory, technological and platform governance contexts that facilitate online harms, interrogating the adequacy of existing legislative and platform responses. In doing so, it bridges the gap between academic research, policy and industry, offering a practical framework for understanding and responding to online harms. This book is essential reading for scholars, policymakers, practitioners and technology companies seeking to create safer and more inclusive online environments for women and girls.