Alva Bryan "Red" Lasswell (January 3, 1905 – October 28, 1988) was a United States Marine Corps linguist and cryptanalyst during World War II.

In April 1943, Lasswell helped decrypt the coded itinerary of Admiral Isoroku Yamamoto, leading to his interception by Army Air Forces fighter planes near Rabaul.

Assigned to teach FBI agents small arms marksmanship, he received a letter of commendation from Director J. Edgar Hoover.

In September 1938, Lasswell was sent to Station CAST in the Philippines to relieve Lieutenant Joseph Finnegan and receive cryptology training.

[3] After the Battle of the Coral Sea in May 1942, the team of intelligence officers at Station HYPO were hard at work trying to determine what the Japanese Navy would do next.

After 18 hours of effort by the team at Station HYPO, it turned out to be the itinerary for a visit by Admiral Isoroku Yamamoto to the Japanese front lines near Rabaul and the northern Solomon Islands.

Lasswell and his supervisor Jasper Holmes delivered the translated message to the Pacific Fleet intelligence officer Edwin Layton, who in turn passed it on to Admiral Nimitz.

[4] Lasswell Hall at Fort George G. Meade in Maryland, the headquarters of Marine Corps Forces Cyberspace Command, was named in his honor.