Cassin's Kingbird has a gray head and breast, a white throat, and a yellow belly. It catches flying insects from perches in open country.
A white throat stands out against the gray head and breast, and the underparts are lemon-yellow.
It spots flying insects from high trees or branches and sallies out to catch them. It uses places with both tall nesting trees and open foraging space.
An extinction-risk assessment has not been added yet.