For the first time at an international championship, Molly Scott competed at the European Youth Olympic Festival 2015 in Tbilisi , where she finished fifth in the 100-meter hurdles in 13.85 s and with the Irish 4-by-100-meter relay in the final did not reach the goal. The following year she won the bronze medal in the hurdles sprint at the European Youth Championships held there for the first time in 13.51 s and then took part with the relay at the U20 World Championships in Bydgoszcz , where she finished fifth in 44.82 s. In 2017 she reached the semi-finals at the U20 European Championships in Grosseto , where she was eliminated with 14.27 seconds, while she finished fourth in the relay in 44.47 seconds. Also at the U20 World Championships in Tampere the following year, she reached the semi-finals in the hurdles and was eliminated there with 13.94 s, while she won the silver medal in 43.90 s with the relay. In 2019, she finished eighth in the 100-meter run at the U23 European Championships in Gävle in 11.70 s and was eliminated in the semifinals with 13.59 s. With the relay she finished fourth again in 44.32 s.
In 2019 Scott became Irish indoor champion in the 60-meter run.
Personal bests
100 meters: 11.58 s (+1.0 m / s), July 27, 2019 in Santry
60 meters (hall): 7.32 s, February 17, 2019 in Abbotstown
100 m hurdles: 13.59 s (+1.3 m / s), July 12, 2019 in Gävle
60 m hurdles (hall): 8.34 s, February 8, 2019 in Athlone