The Acadian flycatcher (Empidonax virescens) is a small insect-eating bird of the tyrant flycatcher family.
Adults have olive upperparts, darker on the wings and tail, with whitish underparts; they have a white eye ring, white wing bars and a wide bill. The breast is washed with olive. The upper part of the bill is dark; the lower part is yellowish. This bird's song is an explosive peet-sa. The call is a soft peet. They also have a call similar to that of the northern flicker A unique two-note song described as "ka-zeep", and its location in its preferred habitat, are two features that help to identify this species