The San Diego Science Festival (SDSF) is a collaboration of more than 125 leading science and educational organizations in the San Diego region that include private industry, K-12 schools/districts, higher education, private foundations, media partners, and concerned individuals. All Festival events are organized by community members and the University of California, San Diego.

The first annual festival, held in Spring 2009, featured activities that impacted more than 75,000 individuals, including 50,000 who attended the inaugural Expo Day. The 2010 San Diego Science Festival featured hundreds of hands-on science related activities during the week-long event of March 20-27. The 2011 San Diego Science Festival will continue the 2010 tradition of a major Expo Day held at PETCO Park, home of the San Diego Padres, who are festival partners along with the City of San Diego. Almost all events are free and open to the public.

The San Diego Science Festival is organized by the University of California, San Diego, with the support of hundreds of community collaborators, to motivate students of all ages across the region to enter science educations and careers, and inform the public about how important scientific discoveries influence the quality of their everyday lives. UC San Diego was recently awarded a $3 million National Science Foundation (NSF) grant to fund the year-round San Diego Science Festival. In addition, the NSF grant will be utilized over its three-year life to support three other Festival sites:  San Francisco through UC San Francisco, Cambridge, Massachusetts through the MIT Museum, and Philadelphia through The Franklin Institute. It also establishes the national Science Festival Alliance to generate and support science festival start-ups across the entire nation.