Eupterote diffusa is a moth in the Eupterotidae family. It was described by Walker in 1865. It is found in India and Sri Lanka. The wingspan is 58-66 mm. Adults are similar to Eupterote mollifera. The wings vary in colour from greyish white to dull ochreous brown or pale primrose-yellow. The postmedial line is single, curved on both wings and much nearer to the margin than in mollifera. The waved lines are fairly distinct or obsolescent, as are the spots and outer waved line.