The report estimates that social enterprises could provide £160m of fair-trade produce, £150m of property development and £90m of waste and recycling services for the games.
They could also offer transport worth £60m, medical services worth £25m and community engagement advice worth £15m.
Social Enterprise London wrote the report in collaboration with public sector consultancy Rocket Science. It was co-funded by the Office of the Third Sector.
The social enterprise support organisation hopes that all the coffee, tea and chocolate consumed at the games will be supplied by Cafe-Direct and Divine Chocolate, and that Greenwich Leisure will manage the Olympic aquatic centre. Hackney Community Transport could provide transport for volunteers and staff. All four are social enterprises.
But the report also says social enterprises need to speed up staff training and form themselves into networks capable of providing joint products or services.
Sinead McBrearty, the report's author and deputy chief executive of Social Enterprise London, said sales and marketing needed particular attention.
A Cabinet Office spokesman said it was important that social enterprises had "fair opportunities" to compete for contracts so that social and environmental objectives became the lasting legacy of the games.