Psamathocrita argentella is a moth of the Gelechiidae family. It was described by Pierce and Metcalfe in 1942. It is found in Great Britain, where it has been recorded from salt-marshes in Hampshire, Isle of Wight, Sussex and Dorset. The wingspan is 10–11 mm. The forewings are white with some black scales, forming a small marking at three-fourths. The hindwings are greyish-white. The larvae feed on the flowers and seeds of Agropyron pungens.