Leutnant Karl Thom (19 May 1893 – 3 March 1945), was a German World War I flying ace credited with 27 victories.

He was serving with Mounted Rifle Regiment Number 10 when World War I began.

[1] He joined his new squadron at approximately the same time as its new leader, Staffelführer Eduard Ritter von Schleich, who took charge on 26 May.

[6][7] He marked his Albatros airplane's fuselage with a large black capital block 'T' with pronounced serifs to identify himself in the air.

[1] October brought changes, as Jasta 21 received Oskar Freiherr von Boenigk as the new commanding officer[7] and Fokker D.VIIs as new airplanes to replace the Albatros D.Vs that had been the squadron's craft.

[9] On 11 October, Thom was awarded the Military Merit Cross, Prussia's and Germany's highest decoration for valorous enlisted men.

[3] He had previously been awarded the Member's class of the Royal House Order of Hohenzollern.

[1] Thom's return to the victory rolls roughly coincided with Jasta 21's adoption of Fokker D.VIIs, replacing its Albatros D.Vs.