The Sun Red SR21 is a Spanish-made sportscar which competed in the International GT Open between 2007 and 2009.

[1] The SR21 was built under FIA GT2 specifications, although it was never an homologated as such due to it not being a production GT car.

Manufacturer Sunred Engineering entered the car in the 2007 International GT Open season.

The car was driven the full season by Juan Ramon Zapata and was joined by different guest drivers each race weekend.

[2] Óscar Fernández and José-Manuel Perez-Aicart drove the full-time entry in the 2008 International GT Open season.