The grey falcon (Falco hypoleucos) is a medium-sized falcon native to Australia, possibly the rarest. It is uncommon throughout its range and is currently classified as Vulnerable.
The species has mainly grey upperparts and white underparts, darker on the tips of the flight feathers and with a yellow cere. Young birds are darker. Adults have a body length of 30–45 cm and a wingspan of 85–95 cm, and weight 350–600 g. Females are larger. The call of the grey falcon consists of hoarse chattering, clucking and whining sounds, similar to the peregrine falcon but slower and deeper. Calls include a loud, slow "kek-kek-kek" or "kak-ak-ak-ak".