Résumé : The subject of this thesis is the practice of curating art online, or, to put it differently, how and by whom art is curated online. We begin by placing the online curating of art in the wider context and history of curating as a profession. Eleven online curating platforms are then discussed as case studies. The selected case studies are divided in two groups: websites that allow everyday Internet users to curate art online, on the one hand, and websites that were created by and/or allow professional curators to curate art online, on the other. The websites are then divided into subcategories by grouping websites with similar structures and/or goals together. For each and every one of those case studies, we study how they were built, what they have to offer to their users, what their definition of curating is and compare them with the other case studies. Our methodology is based on a hands-on approach as well as on bibliographic research and, in some cases, interviews with the websites’ creators. The results of this research show that most of the art curating online happens in 2D and that the social element is present on every website whilst being dominant on some of them. Some websites experiment with the possibilities offered by the Internet while others decided to adopt the habits and rules of in-gallery exhibitions. Our research also shows that copyright is an extremely complex issue, an issue that remains mostly unanswered online. Finally, we also discovered that the main difference between online exhibitions curated by everyday Internet users and art professionals lay in the fact that exhibitions curated online by art professionals held much more artistic and historic information and offered more knowledge than those curated by everyday Internet users.