Like most space endeavors, Sputnik 1 was a team effort. However, Mikhail Khomyakov is typically credited with doing most of the design work on Sputnik 1.
Sputnik 1 was designed by the Russian space program organization, OKB-1, to be a very simple satellite because the ongoing satellite project "Object D" was behind schedule. The deadline for launch of a satellite was late 1957 because the United States had declared that the first American satellite launch would occur during the International Geophysical Year between July 1, 1957 and December 31, 1958. In order to beat the United States, a group of scientists and engineers, including Mikhail Khomyakov, Nikolai Kutyrkin and Georgy Grechko, were given orders to make Sputnik 1, a simple satellite.