The Pacific-slope Flycatcher (Empidonax difficilis) is a small insectivorous bird of the family Tyrannidae. It is native to coastal regions of western North America as far north as British Columbia, but is replaced in the inland regions by the Cordilleran Flycatcher. These two species were formerly considered a single species known as Western Flycatcher. In winter, both species migrate south to Mexico, where they are virtually indistinguishable from one another.

In plumage, the Pacific-slope Flycatcher is virtually identical to the Cordilleran Flycatcher, and differs only subtly from most Empidonax flycatchers in North America, but its breeding habitat and call are different. In summer, the Pacific-slope Flycatcher inhabits deciduous or mixed woodlands, hawking for insects from a hidden perch.