Cyathea croftii is a species of tree fern endemic to Manus Island in the Admiralty Islands, where it grows in damp forest on steep slopes at an altitude of about 500 m. It is relatively uncommon in the wild.

The rachis and stipe are often light green, particularly when young.

They are slender and covered with glossy brown scales towards the base.

Sori are small and occur in rows, one along each side of the pinnule midvein.

The specific epithet croftii commemorates pteridologist James R. Croft (b.