Euchloe guaymasensis, the Sonoran marble or Sonoran white, is a species of butterfly in the family Pieridae. It is native to Sonora in Mexico and has been seen once in Arizona in the United States. This butterfly has a wingspan of 31 to 37 millimeters. The upperside is pale yellow. The forewing has a black tip and a black bar toward the front edge. The underside is marbled with green. This species occurs in rocky desert habitat. Its host plant is western tansymustard (Descurainia pinnata). Adults fly in February and March.