The Stepford Cuckoos are a set of fictional mutant psychically linked quintuplets (Celeste Cuckoo, Esme Cuckoo, Irma "Mindee" Cuckoo, Phoebe Cuckoo, and Sophie Cuckoo). The alphabetical order of the Cuckoos' first names corresponds with their ages, with Celeste being the firstborn and Sophie being the youngest. Originally calling themselves the Five-in-One, with the deaths of Esme and Sophie the remaining sisters are now known as the Three-in-One.
They are students at the Xavier Institute for Higher Learning and appear in comic books published by Marvel Comics.
Their name is based on the novels The Midwich Cuckoos, by John Wyndham, and The Stepford Wives by Ira Levin.
First appearing in New X-Men, vol. 1 #118, they were created by Grant Morrison. Their origin, as the artificially created "daughters" of Emma Frost, is revealed in X-Men: Phoenix—Warsong.
Esme and Sophie were among the feature characters in the 2011 two-issue limited series Chaos War: X-Men.