On 7 December 1941, the 61st stepped up to defend the Southeastern United States from anticipated enemy air attack while it converted to the Republic P-47 Thunderbolt aircraft and prepared to deploy overseas.

The squadron was given fuselage code "HV" and operated from several RAF stations during the war, flying the P-47C Thunderbolt as an VIII Fighter Command bomber-escort unit initially for B-17 Flying Fortresses and beginning in 1944 for B-24 Liberators attacking enemy targets in Occupied Europe.

Zwarte zaterdag: on 5 August 1944 8 planes of the 61st squadron attacked a passenger train near the Dutch village Beilen (Drenthe).

Initially equipped with P-47D Thunderbolts, being replaced with long-range P-51H Mustangs, originally developed for Twentieth Air Force bomber escort missions in the Pacific Theater.

In 1953 the Squadron was relocate to Ernest Harmon AFB in Newfoundland where it became part of the DEW (Defense Early Warning) system.

On 1 November 1991, the host 56th Tactical Training Wing at MacDill implemented the Objective organization plan, and the subsequent re-designation of units led to the 61st becoming simply the 61st Fighter Squadron, and being assigned to the new 56th Operations Group.

The end of the Cold War led to the BRAC commissions, and the downsizing of the Air Force to a smaller organization.

It was decided that the 63d Fighter Squadron would inactivate and transfer its Block 42s to the 61st FS, and which, due to its seniority and historical heritage, would remain active.

This article incorporates public domain material from the Air Force Historical Research Agency