| Named By: | C. J. O. Harrison & C. A. Walker in 1973 |
| Time Period: | Early Cretaceous, 138 Ma |
| Location: | England, Sussex |
| Size: | Unknown due to lack of fossil remains |
| Diet: | Uncertain |
| Fossil(s): | Partial right humerus |
| Classification: | | Chordata | Dinosauria | Saurischia | Theropoda | Euornithes | |
Wyleyia is a prehistoric bird genus with a single species, Wyleyia valdensis, known from the early Cretaceous period of England. Even this is only known from a single damaged right humerus. It has been named to honor J. F. Wyley, who found the specimen in Weald Clay deposits of Henfield in Sussex (England). The specific name valdensis means "from the Weald".
The bone was found in the Hastings Beds, a series of Valanginian deposits, dated to between 140 and 136 million years ago.
Sometimes believed to be from a non-avialan coelurosaur, it is now generally accepted as an early bird, although its exact systematic position is unresolved. It has been proposed to be an enantiornithine or an early neornithine palaeognathe. C.J.O. Harrison and C.A. Walker found it
"... advisable to consider the new genus incertae sedis until further evidence of affinity is forthcoming."