Sport Relief aims to transform the lives of poor and vulnerable people, both at home and across the world's poorest countries, by raising money through a one-mile run, other sporting events and a live TV broadcast.
DiscountVouchers will donate 10p to the charity for every social networker that becomes a fan of the discount voucher site on Facebook before midnight on March 21.
"Sport Relief is a fantastic cause and we are willing to donate up to £50,000 to aid the charity," said Simon Terry, MD of DiscountVouchers.
"However, it is up to the public how much we spend - the more people who become fans, the money we will donate!
Visit the DiscountVouchers Facebook page to become a fan.
See also: Comic Relief offers digital red noses