On 29 January 2019, Dobbie scored his ninth hat-trick since his return to the "Doonhamers", this time in a 3–0 win at home to Scottish Premiership club Dundee, in the fourth round replay of the 2018–19 Scottish Cup, his fifth treble of the season. Dobbie scored his goals after 12, 27 and 74 minutes, the first being a "looping long-range effort" from 25 yards. On 31 January, he was presented with the Scottish Championship Player of the Month award for January 2019. On 10 February, in the next round of the Scottish Cup, he scored an "outrageous" goal from around 30 yards to equalise against Aberdeen at Pittodrie, although this time the top-tier side responded and eventually won 4–1 to eliminate Queen of the South from the competition.