Born in Westerholt, Westphalia he was the second of four sons of a land manager. He graduated from Hindenburg school in Buer in 1932 and joined a Lufthansa aviation school before transferring to the new and technically illegal Luftwaffe in 1933. Despite a bad crash he completed his training in Italy in 1935 and was posted to the 1st Fighter Group, then based at Doberitz.
During the Spanish Civil War he commanded a Kondor Legion squadron at El Ferrol from mid-1937, flying the Heinkel He-51s he completed over 300 missions. In 1939 he was decorated with the Spanish Cross.
Just before the outbreak of WW II he was promoted to Captain and took part in ground-attack missions in Poland. He was transferred to a fighter unit in April 1940, Jagdgeschwader 27 (JG-27). Two of his brothers were also pilots, Paul was killed in 1942 and Wilhelm in 1943.
From June 1940 he flew as Gruppenkommandeur with JG-23 and then JG-26 fighting the Battle of Britain, flying a Me-109 from bases in the Pas de Calais. In July he was promoted to Major and then to Kommodore and in November to Oberstleutnant (Lieutenant Colonel). By the end of that clash he had 58 victories. He had been shot down only once, on June 21, 1941. Following a last official victory in November 1941 (number 97) he was chosen by Hermann Göring to become General der Jagdflieger, succeeding Werner Mölders who had recently died in an air-crash (and had only just succeeded Ernst Udet), and Galland promoted to become the youngest General Leutnant in Germany. No longer flying operationally he organized the air protection for the 'Channel Dash' of the Scharnhorst, Gneisenau and the Prinz Eugen and was then responsible for the air defence of Germany. In 1942 he also flew one of the first Me-262 prototypes and became an enthusiastic supporter of the aircraft.
Typically open and blunt, a repeated critic of his superior Göring, he was soon distanced from the Nazi hierarchy, following the 'Fighters Revolt' meeting of January 1945 he was relieved of his command, Gordon Gollob succeeded him. In March he formed the elite JV-44 (Jagdverband), leading them until his last mission on April 26, 1945 when his craft was badly damaged and then crashed on landing and Galland was badly injured. He ended the war with 103 victories and the Knights Cross (Ritterkreuz) with diamonds, swords and oakleaves.
He was captured on May 14, 1945 and remained a POW until 1947. He first post-war job was for the RAF, lecturing on tactics. From 1948-55 he and other ex-Luftwaffe experts worked as consultants to the Argentinian airforce. He married Sylvinia von Donhoff in February 1954. He returned to Germany to found an aviation firm and consultancy.
His autobiography, From First to Last, was published in 1957.