The supermarket firm invited organisations from across the UK to apply for a share of £100,000.
The RNLI put in an application for a Bags of Help Centenary Grant and were one of three community projects shortlisted by Tesco staff in North Yorkshire.
Customers across the county then voted in store for their preferred project using tokens given out at checkouts, with Scarborough’s lifeboat service scooping the top prize in the region.
The organisation will use the money to carry out training and continue it’s life-saving work on the Yorkshire Coast.
Andy Volans, lifeboat operations manager in Scarborough, said: "On behalf of Scarborough RNLI, we are deeply grateful to Tesco for this large donation which will help save lives on our coast".
Tesco’s community funding is given to projects which have a positive impact on their local area such as improving outdoor spaces, volunteering or bringing people together,
Administration of the funding is managed by charity, Groundwork, which specialises in transforming communities and the local environment for the better.