Jesse Antoine Marcel Sr. (May 27, 1907 – June 23, 1986) was a major in the United States Air Force (later a lieutenant colonel in the Reserves) who helped administer Operation Crossroads, the 1946 atom bomb tests at the Bikini Atoll.

[2]: 39 [3]: i Marcel was the first military officer tasked with investigating the 1947 Roswell incident, where supposed "flying disc" debris was later identified as pieces of a weather balloon.

The incident was largely forgotten until 1978, when Marcel, then a retired lieutenant colonel, told ufologist Stanton Friedman that he believed the Roswell debris was extraterrestrial.

[2]: 28 After Marcel graduated from high school, he worked at a general store and attended a few graphic design classes at Louisiana State University.

Marcel began working as a draftsman and cartographer for the Louisiana Highway Department, the Army Corps of Engineers, and the Shell Oil Company.

[6] On July 26, 1946, Brigadier General Roger M. Ramey authored a letter of commendation complimenting Marcel's performance during Operation Crossroads.

[17] On Monday, July 7, Roswell Army Air Field was contacted by Sheriff George Wilcox, who reported that a local rancher had recovered a crashed "flying disc".

[19]: 26  Roswell Army Air Field issued a press release announcing the recovery of a 'flying disc' and naming Marcel as the responsible officer.

[22] Marcel was quoted as saying, "[We] spent a couple of hours Monday afternoon [July 7] looking for any more parts of the weather device, [and] we found a few more patches of tinfoil and rubber.

[19] On September 20, 1980, the TV series In Search of... aired an interview where Marcel described his participation in the 1947 press conference:[24] They wanted some comments from me, but I wasn't at liberty to do that.

[15]: iii [28][15]: 25  During June and July 1947, Mogul balloons had been test-launched at Alamogordo Army Air Field (now Holloman AFB) and White Sands Missile Range.

This fact, along with the initial mis-identification and subsequent rumors that the 'capture' of a 'flying disc' occurred, ultimately left many people with unanswered questions that have endured to this day.

[15]: 316 In December 1947, while still in active duty, Major Marcel received a promotion to the rank of lieutenant colonel in the Air Force Reserve.