The following is a listing of the Bombardment Groups and Squadrons which operated the B-17 during World War 2:
4th, 7th, 18th, and 391st Bomb Squadrons
Trained on B-17s and conducted early patrols, but first entered
combat from England in May 1944 equipped with B-24s.
Transitioned to B-17s September 1944. Based at Mendlesham,
UK. Inactivated August 1945.
322nd, 323rd, 324th, 401st Bomb Squadrons
Formed in US in April 1942. Based at Bassingbourn, UK. Inactivated at end of 1945.
325th, 326th, 327th, and 407th Bomb Squadrons
Formed in January 1942. Based at Bovington, then at Alconbury, and finally at Podington in the UK. Absorbed into 306th BG.
331st, 332nd, 333rd, and 410th Bomb Squadrons
Formed June 1942, based briefly at Earls Colne then moved to Bury
St Edmunds, Rougham, UK. Inactivated December 1945
334th, 335th, 336th, and 412th Bomb Squadrons
Formed in early 1942. Based at Alconbury and Framilingham in the spring of 1943, but quickly moved to Horham, UK. Inactivated August 1945.
337th, 338th, 339th, and 413th Bomb Squadrons
Activated October 1942. Based at Snetterton Heath, UK.
349th, 350th, 351st, and 418th Bomb Squadrons
Formed in June 1942. Based at Podington and then at Thorpe Abbot, UK.
358th, 359th, 360th, and 427th Bomb Squadrons
Formed in February 1942, based at Molesworth, UK, inactivated July 1945.
364th, 365th, 366th, and 422nd Bomb Squadrons
Formed in March of 1942. Based at Grafton Underwood (Chelveston??) in UK. Deactivated December 1946.
367th, 368th, 369th, and 423rd Bomb Squadrons
Formed in March of 1942, based at Thurleigh in UK, disbanded December 1946.
508th, 509th, 510th, and 511th Bomb Squadrons
Formed in October of 1942, based at Polebrook, UK, inactivated August 1945.
524th, 525th, 526th, and 527th Bomb Squadrons
Formed in November 1942, based at Kimbolton, UK, inactivated July of 1945.
532nd, 533rd, 534th, 535th Bomb Squadrons
Formed in November 1942. Based at Ridgewell, UK. Inactivated Aug 1945.
544th, 545th, 546th, and 547th Bomb Squadrons
Formed in December 1942, based at Grafton Underwood, UK, inactivated February 1946.
548th, 549th, 550th, 551st Bomb Squadrons
Formed in February 1953, based at Great Ashfield, UK, inactivated August 1945.
560th, 561st, 562nd, and 563 Bomb Squadrons
Formed in December 1942, based in Knettishall, UK. Inactivated September 1945
568th, 569th, 570th, and 571st Bomb Squadrons
Formed in January 1943. Based at Framlingham, UK. Inactivated in August of 1945.
600th, 601st, 602nd, and 603rd Bomb Squadrons
Formed March 1, 1943, based at Nuthampstead, UK, inactivated Sept 1, 1945.
612th, 613th, 614th, and 615th Bomb Squadrons
Formed April 1943, based at Deenethorpe, UK, inactivated August 1945.
708th, 709th, 710th, and 711th Bomb Squadrons
Formed spring 1943, based at Rattlesden, UK, inactivated November 1945
728th, 729th, 730th, and 731st Bomb Squadrons
Formed June 1943, based at Deopham Green, UK., inactivated August 1945
748th, 749th, 750th, and 751st Bomb Squadrons
Formed July 1943, based at Glatton, UK, inactivated August 1945
812nd, 813rd, and 814th Bomb Squadrons.
Established at Alconbury, UK August 1943. A composite group with 2 squadrons of B-17s and one of B-24s. Conducted Pathfinder missions using H2X radar. Inactivated September 1945.
832nd, 833rd, 834th, and 835th Bomb Squadrons
Converted from B-24s to B-17s Aug 1, 1944, based at Sudbury, UK., Inactivated November 1945.
836th, 837th, 838th, and 839th Bomb Squadrons
Formed initially with B-24s, transitioned to B-17s July 1944 and based at Lavenham, UK. Inactivated November 1945.
848th, 849th, 850th, and 851st Bomb Squadrons
Transitioned from B-24s to B-17s in August 1944, based at Eye, UK, inactivated November 1945.
860th, 861st, 862nd, and 863rd Bomb Squadrons
Formed as a B-24 group, but only used them for 7 weeks before converting to B-17s, based at Depach and Little Walden, UK. Inactivated August 1945.
20th, 49th, 96th, and 429th Bomb Squadrons
Arrived in Algeria April 1943. Flew out of Tunisia and was then based at Foggia, Italy from December 1943.
340th, 314st, 342nd, and 414th Bomb Squadrons
Initially part of the 8th AF, but reassigned to 12th AF in November 1942 in North Africa and then to Italy. Disbanded October 1945.
346th, 347th, 348th, and 416th Bomb Squadrons
Moved to North Africa early 1943. To Tortorella near Foggia, Italy. Deactivated in Italy November 1945.
32nd, 352nd, 353rd, and 419th Bomb Squadrons
Originally part of 8th AF, but moved to North Africa late 1942. Inactivated August 1945.
772nd, 773rd, 774th, and 775th Bomb Squadrons
Formed August 1943, based at Foggia, Italy, Inactivated August 1945.
815th, 816th, 817th, and 840th Bomb Squadrons
Formed September 1943, based at Tortorella and then based permanently at Sterparone, Italy. Inactivated September 1945.
28th, 30th, and 93rd Bomb Squadrons
Based in Philippines at beginning of war, withdrew to Australia and then to Java. Returned to US in late 1942 and became a replacement training unit before disbandment in April of 1944 and reformation as a B-29 unit
63rd, 64th, 65th, and 403rd Bomb Squadrons
Joined 5th AF in Pacific in March 1942. Participated mainly as a replacement unit for the 7th and 19th BGs, but did see action in the anti-shipping role. Transitioned to B-24s in mid 1943.
31st, 23rd, 72nd, and 394th Bomb Squadrons
Initially based in Hawaii at time of Pearl Harbor attack. Flew patrol missions for 11 months, then moved to Espritu Santo in the Solomons, and with a mix of B-17s and B-24s fought in the Solomons and Philippines campaigns as part of the 13th Air Force
26th, 42nd, 98th, and 431st Bomb Squadrons
Operated at Midway and then to New Hebrides. Returned to USA in March of 1943 for conversion to B-24s.
9th, 436th, 492nd, 493rd Bomb Squadrons , plus 24th Combat Mapping Squadron.
Operated in Philippines, Java, Netherlands East Indies at beginning of the war, then moved to India as part of the 10th Air Force. Converted to B-24s at end of 1942.
These groups served exclusively in the continental United States either as training units or on coastal patrol.
Initially formed at the Caribbean Air force and redesignated Sixth Air Force in February of 1942.
A lot of you have questions about relatives or friends who flew in B-17s during the war. There is a good website which gives lots more information on B-17 squadron assignments than is listed here. It is known as Heavy Bombers. They also have indexes to web sites operated by veterans which point to information about specific planes and specific squadron histories and perhaps pointers to specific veterans themselves. Go and check it out!