We examine the influence of founders’ prior shared international experience on the timing of their new ventures’ first entry into foreign markets. We propose that this experience, which is gained by founders working concurrently for the same international firm prior to the founding of the current company, provides them with shared knowledge and routines that they can use to enter foreign markets for the first time earlier in the venture’s life. Further, we propose that founders’ diversity strengthens this relationship, because diverse groups of founders have a broader range of knowledge, skills, and perspectives, which facilitates the adaptation of their prior shared international experience to their new venture setting. This is likely to further reduce the time it takes them to enter foreign markets for the first time. We also argue that industry dynamism weakens the relationship between founders’ prior shared international experience and the time to first foreign market entry, because this type of experience is likely to become obsolete in a rapidly changing environment. Finally, we hypothesize that early internationalizers enjoy higher performance than late internationalizers. We test these predictions using a sample of Swedish new ventures. Our results contribute to the literatures on founders’ shared experience and early internationalization.