Online emotional experiences and their relationship to cognitive states are of growing interest. This study investigates one emotional experience – enjoyment – and its impact on informal online learning. The concept of enjoyable online learning, namely online learning that is not part of a formal instructional undertaking, has not been well studied or understood. The study treats enjoyment as a complex and multi-dimensional construct. A field study was conducted with an operational museum website and 1,815 participants. A cross-over experimental design was employed. Structural equation models were constructed to evaluate the relationship between the web enjoyment experience and informal online learning outcomes. This relationship was significant for all three experimental conditions. Analysis also showed relationships among the website design feature of interactivity, the user’s level of enjoyment and informal learning outcomes: (i) the degree of interactivity influences the level of enjoyment; (ii) the degree of interactivity influences informal learning outcomes. Not all results, however, were in the expected direction. The study points to the need for more research in this complex area.