The squadron was re-formed 16 May 1939, on board the aircraft carrier HMS Argus for service in Egypt.
It was based initially at RAF Helwan at Helwan, Cairo Governorate.
On 26 May, "B" Flight was detached and sent to Sudan.
The squadron did not receive its aircraft, obsolescent Gloster Gladiator biplane fighters, until June.
After Italy entered the war on 10 June 1940, the squadron was soon in action, defending Egypt from Italian bombers. "
B" Flight became part of No.
14 Squadron RAF on 30 June.

In January 1941, the squadron joined Allied forces in the Battle of Greece, providing air cover and offensive support over Albania.
It later took part in dogfights as part of the air defence of the Athens area.
With the defeat of the Allied campaign on the Greek mainland, 112 Sqn withdrew to Crete and then to Egypt, from where it rejoined the North African Campaign, supporting the Eighth Army.
For much of the remainder of the war, the squadron was part of No.
239 Wing, with No.
3 Squadron RAAF, No.
250 Squadron RAF, No.
260 Squadron RAF and No.
450 Squadron RAAF.

During July 1941, the squadron was one of the first in the world to become operational with the Curtiss Tomahawk, which it used as a fighter and fighter-bomber.
Inspired by the unusually large air inlet on the P-40, the squadron copied the "shark's mouth" logo painted on some German Messerschmitt Bf 110s of Zerstörergeschwader 76 earlier in the war. (
This practice was later followed by P-40 units in other parts of the world, including the Flying Tigers, American volunteers serving with the Chinese Air Force.)
In December, the Tomahawks were replaced by the improved P-40 Kittyhawk, which the squadron used for the remainder of its time with the Desert Air Force, often as a fighter bomber.

The squadron had many personnel from the air forces of Poland, Australia, Canada and New Zealand.
Another member was the British ace Neville Duke (later prominent as a test pilot).
For most of 1942, it was commanded by the highest-scoring Australian ace of World War II, Clive Caldwell, the first Empire Air Training Scheme graduate to command a British unit.
He was succeeded by Billy Drake, the highest-scoring RAF P-40 pilot and the second-highest-scoring British Commonwealth P-40 pilot, behind Caldwell.
Later in the war, an increasing number of South African pilots joined the unit.

After the invasion of Sicily on 10 July 1943, the squadron moved to the island and onto the Italian mainland in September.
 In June 1944, the Kittyhawks were replaced by the North American Mustang Mark III and from February 1945, Mustang Mk IVs.
The squadron remained in Italy at Lavariano as part of the occupying forces, until disbanding on 30 December 1946 at Treviso.
By the end of the war some 206 air victories had been claimed by the squadron and 62 destroyed on the ground.
The squadron was re-formed 16 May 1939, on board the aircraft carrier HMS Argus for service in Egypt. It was based initially at RAF Helwan at Helwan, Cairo Governorate. On 26 May, "B" Flight was detached and sent to Sudan. The squadron did not receive its aircraft, obsolescent Gloster Gladiator biplane fighters, until June. After Italy entered the war on 10 June 1940, the squadron was soon in action, defending Egypt from Italian bombers. "B" Flight became part of No. 14 Squadron RAF on 30 June.
In January 1941, the squadron joined Allied forces in the Battle of Greece, providing air cover and offensive support over Albania. It later took part in dogfights as part of the air defence of the Athens area. With the defeat of the Allied campaign on the Greek mainland, 112 Sqn withdrew to Crete and then to Egypt, from where it rejoined the North African Campaign, supporting the Eighth Army. For much of the remainder of the war, the squadron was part of No. 239 Wing, with No. 3 Squadron RAAF, No. 250 Squadron RAF, No. 260 Squadron RAF and No. 450 Squadron RAAF.
During July 1941, the squadron was one of the first in the world to become operational with the Curtiss Tomahawk, which it used as a fighter and fighter-bomber. Inspired by the unusually large air inlet on the P-40, the squadron copied the "shark's mouth" logo painted on some German Messerschmitt Bf 110s of Zerstörergeschwader 76 earlier in the war. (This practice was later followed by P-40 units in other parts of the world, including the Flying Tigers, American volunteers serving with the Chinese Air Force.) In December, the Tomahawks were replaced by the improved P-40 Kittyhawk, which the squadron used for the remainder of its time with the Desert Air Force, often as a fighter bomber.
The squadron had many personnel from the air forces of Poland, Australia, Canada and New Zealand. Another member was the British ace Neville Duke (later prominent as a test pilot). For most of 1942, it was commanded by the highest-scoring Australian ace of World War II, Clive Caldwell, the first Empire Air Training Scheme graduate to command a British unit. He was succeeded by Billy Drake, the highest-scoring RAF P-40 pilot and the second-highest-scoring British Commonwealth P-40 pilot, behind Caldwell. Later in the war, an increasing number of South African pilots joined the unit.
After the invasion of Sicily on 10 July 1943, the squadron moved to the island and onto the Italian mainland in September.  In June 1944, the Kittyhawks were replaced by the North American Mustang Mark III and from February 1945, Mustang Mk IVs. The squadron remained in Italy at Lavariano as part of the occupying forces, until disbanding on 30 December 1946 at Treviso. By the end of the war some 206 air victories had been claimed by the squadron and 62 destroyed on the ground.
No. 112 Squadron RAF