The launch, which comes after Seoul's first spy satellite was put into orbit from California's Vandenberg Space Force Base in December, was livestreamed on social media platforms X and YouTube.
The Falcon 9 rocket was launched on Sunday and the satellite successfully separated from the launch vehicle 45 minutes later and entered its targeted orbit, the ministry said in a statement.
It made successful communications with a ground station about two hours and 40 minutes after the launch, the ministry added.
The back-to-back launches of reconnaissance satellites come amid a race against North Korea for military capabilities in space.
After two earlier attempts ended in rocket crashes, Pyongyang said in November last year that it used its own Chollima-1 launch vehicle to place the Malligyong-1 reconnaissance satellite in orbit.
North Korea has previously vowed to launch three new spy satellites in 2024.
South Korean Defence Minister Shin Won-sik told reporters North Korea could launch a second spy satellite as early as in mid-April, the Yonhap news agency reported.
Shin's comment was based on the military's observation of North Korea's related activities, South Korean defence ministry spokesman Jeon Ha-gyu told a briefing.
Seoul's second spy satellite is equipped with a synthetic aperture radar (SAR) capable of producing images regardless of weather conditions due to how it processes data.
