Evald Okas (28 November 1915 – 30 April 2011) was an Estonian painter, probably best known for his portraits of nudes.

Okas was born in Tallinn, where he began his artistic career while studying at the State Art School. With the advent of World War II and the Soviet invasion and occupation of Estonia, he was subsequently mobilized into Soviet army, but, like many other Estonians, moved to work battalions in Kotlas, Russia. When the Soviet officials decided to organize the artistic collectives in the Soviet rear in Yaroslavl, several Estonian artists, including Okas, were provided with an opportunity to leave the work battalions and join the artistic ensembles in 1942. The "Yaroslavl artists", as they became to be known, were also the founding members of the Soviet Estonian Artists Union established in 1943. In Yaroslavl Okas befriended the rather well-known Estonian graphic artist Aino Bach and Richard Sagrits who mentored Okas and helped him hone his skills as an artist. By Soviet regulations, however, all artists were expected to paint in the Social Realism genre.