The Blue Noddy (Procelsterna cerulea) is a species of tern in the Sternidae family. It is also known as the Blue-grey Noddy.

It is found in American Samoa, the Cook Islands, Fiji, French Polynesia, Kiribati, Marshall Islands, New Caledonia, Samoa, Tonga (Niua), Tuvalu and Hawaii. It has occurred as a vagrant in Australia and Japan. Its natural habitat is open, shallow seas in tropical and subtropical regions.

The Grey Noddy (Procelsterna albivitta) replaces it to to the south of its range; the two were formerly considered to be a single species but are now often split.