The Cray-1 was a supercomputer designed, manufactured, and marketed by Cray Research. The first Cray-1 system was installed at Los Alamos National Laboratory in 1976, and it went on to become one of the best known and most successful supercomputers in history. The Cray-1's architect was Seymour Cray and the chief engineer was Cray Research co-founder Lester Davis.

In the years 1968 to 1972, Cray was working at Control Data Corporation (CDC) on a new machine known as the CDC 8600, the logical successor to his earlier CDC 6600 and CDC 7600 designs. The 8600 was essentially made up of four 7600s in a box, with an additional special mode that allowed them to operate lock-step in a SIMD fashion.

Jim Thornton, formerly Cray's engineering partner on earlier designs, had started a more radical project known as the CDC STAR-100. Unlike the 8600's brute-force approach to performance, the STAR took an entirely different route. In fact the main processor of the STAR had less performance than the 7600, but added additional hardware and instructions to speed up particularly common supercomputer tasks.

Seymour Roger Cray (September 28, 1925 – October 5, 1996) was an American electrical engineer and supercomputer architect who designed a series of computers that were the fastest in the world for decades, and founded Cray Research which would build many of these machines. Called "the father of supercomputing," Cray has been credited with creating the supercomputer industry. Joel Birnbaum, then CTO of HP, said of him:

Cray was born in 1925 in Chippewa Falls, Wisconsin to Seymour R. and Lillian Cray. His father was a civil engineer who fostered Cray's interest in science and engineering. As early as the age of ten he was able to build a device out of Erector Set components that converted punched paper tape into Morse code signals. The basement of the family home was given over to the young Cray as a "laboratory".

Cray graduated from Chippewa Falls High School in 1943 before being drafted for World War II as a radio operator. He saw action in Europe, and then moved to the Pacific theatre where he worked on breaking Japanese codes. On his return to the United States he received a B.Sc. in Electrical Engineering at the University of Minnesota, graduating in 1949. He also was awarded a M.Sc. in applied mathematics in 1951.