The Star Finch is a small estrildid finch measuring 10-12 cm in length. It features a crimson head and scarlet bill, with yellow-green upper and lower plumage. White spots can be found on the underparts, with a more yellow belly. The upper tail coverts are scarlet and the tail feathers are a brownish scarlet. Females have less crimson on the head and are generally duller than males. Immature Star Finches are olive to brownish in color with a grey face and head. Its common name comes from the broad white spots found under its chin and down its flanks. The Star Finch has a wingspan of 49-56 mm, a bill length of 11-13 mm, and weighs 10-12 grams.