Oh started to make noise as a 14-year-old in 2023. She notched a 9th place finish at the KLPGA's Kyochon 1991 Ladies Open in May. She managed a 16th and a 12th at two other pro events that year. Meanwhile, on the amateur side, she finished 9th at the Korea Women's Amateur, and won the Song Am Cup. More auspiciously, she finished 3rd at the World Junior Girls Championship. She also played her first LPGA event, finishing 64th at the BMW Championship.

It was in 2024, however, when Soomin burst into the public consciousness. She was named to the national team for the first time at the beginning of the year. She made it count at the Singapore Open, the opening event of the KLPGA season. She played brilliantly, astounding the galleries with her steady play and booming drives. After three rounds, she had a three shot lead and looked ready to capture her first win. Had she done it, she would have been the fourth youngest to ever win on the KLPGA and the first amateur since Hye Jin Choi in 2017. It was not to be: she played OK, but Jae Hee Kim was better, and Oh wound up third. Still a spectacular result, and one that has everyone excited about what she might do next.