The funding is part of £530 million earmarked by the government to improve the broadband network.
County council deputy leader Lionel Barnard, who has responsibility for broadband, said: “West Sussex County Council has been doing a lot of work with internet service providers and we are committed to the need to improve broadband in West Sussex.
“A good broadband connection is vital for businesses, many of which are home-based.
“We need to ensure this happens to encourage business development in West Sussex.”
Leader Louise Goldsmith said: “Our aim is to ensure everyone in the county, residents and businesses, have access to a fast broadband connection.
“The funding will help us to achieve this goal.”
There are still many parts of West Sussex where it is not possible to get a usable broadband connection, especially in rural areas.
There are three non-broadband telephone exchanges in West Sussex – East Marden, Plaistow and Sutton.
The funding will be used to cover the gaps in the county which will miss out on super-fast broadband in the commercial roll-out.