The satellite was placed into orbit just over an hour after launch "successfully established communication with an overseas ground station," South Korea's defence ministry said on Friday.
SpaceX ended its livestream of the mission minutes after the rocket's liftoff and then recovery of its core stage booster without showing the South Korean payload's deployment.
In May, South Korea used its own domestically produced Nuri launch vehicle to place a mission-capable satellite into orbit for the first time, but it has contracted with the American company SpaceX to launch a total of five spy satellites by 2025 in an effort to accelerate its goal of having 24-hour watch over the Korean peninsula.
The satellite launched on Friday is an electro-optical and infra-red device, while the four following satellites are due to feature synthetic aperture radar (SAR), which can "see" through cloud cover and at night.
South Korea has relied on its American allies for satellite intelligence, but is planning an array of reconnaissance and military communications satellites as part of a broader push into space.
After two earlier attempts ended in rocket crashes this year, North Korea used its own Chollima-1 launch vehicle to place the Malligyong-1 reconnaissance satellite in orbit.
Pyongyang has yet to release any imagery from that satellite, and analysts say its full capabilities are unknown.
North Korean state media says the craft has already photographed a range of "target regions" ranging from the White House and Pentagon to US military bases in South Korea, Guam, and Hawaii, and the South Korean capital, Seoul.
