His father Seán 'Jack' Clancy (a native of Kilrush, County Clare) was principal of the primary school he attended, and he attended Christian Brothers Secondary School in Mitchelstown for three years, before moving to St Flannan's College in Ennis to complete the Leaving Certificate.

[4] As a search and rescue pilot, Clancy was commander of a crew who received the Marine Medal for Meritorious Service in 2002.

In 2017, he was appointed as General Officer Commanding (GOC) of the Irish Air Corps and Director of Military Aviation (DFHQ).

[6] Clancy became the first Air Corps officer to be appointed as Chief of Staff by the government, and the second from outside the Irish Army (his predecessor Vice Admiral Mark Mellett was from the Naval Service).

He graduated from the Defence Forces Command and Staff College with the Lt Gen Tadgh O'Neill Award (for best student of combined military and MA components).