Dennis is a moderately popular boys' name in England & Wales, ranking #396 in 2001 with 58 recorded births. The name reached its all-time peak in 2017 with 139 births ranking #343. In 2001, approximately 1 in every 4,962 boys born was named Dennis. STABLE Recent data shows the name is currently stable.
Dennis is the familiar English form of a Greek-rooted name meaning "devoted to Dionysus". In modern use, the classical mythological root matters much less than the name's long, stable history.
The name spread through Christian tradition, especially through Saint Denis and later forms across Europe. In English it became a dependable twentieth-century classic.