A habitational surname, from Old English.
"The local history book noted that Hayden is a habitational surname derived from an Old English place name."
Hayden originally functioned as a place name derived from the Old English words for "hay" and "valley," though some sources suggest it may instead come from the Middle Dutch term for "heathen." The surname likely entered English usage by adopting this geographical or descriptive label rather than evolving directly from its root components.