In recent years, the rapid increase in the dissemination of offensive and discriminatory material aimed at women through social media platforms has emerged as a significant concern. This trend has had adverse effects on women’s well-being and their ability to freely express themselves. The EXIST campaign has been promoting research in online sexism detection and categorization in English and Spanish since 2021. The fourth edition of EXIST, hosted at the CLEF 2024 conference, consists of three groups of tasks, which are a continuation of EXIST 2023: sexism identification, source intention identification, and sexism categorization. However, while EXIST 2023 focused on processing tweets, the novelty of this edition is that the three tasks are also applied to memes, resulting in a total of six tasks. The "learning with disagreement" paradigm is adopted to address disagreements in the labelling process and promote the development of equitable systems that are able to learn from different perspectives on the sexism phenomena. The 2024 edition of EXIST has exceeded the success of previous editions, with the participation of 57 teams submitting 412 runs. This lab overview describes the tasks, dataset, evaluation methodology, participant approaches and results.