King hit the scoreboard in each of the first three quarters at Marvel Stadium on Sunday as the Saints posted a comfortable 14.9 (93) to 8.9 (57) victory.
It put Ross Lyon's sixth-placed side a win and percentage clear of ninth with two rounds left in the race for top-eight spots.
The Tigers are all but out of finals contention after failing to arrest a horror run of form at the Docklands venue.
They have lost seven and drawn one of eight visits since former coach Damien Hardwick famously declared "I hate coming here" in 2021.
Noah Balta had no way of stopping Saints spearhead King, who fired in his second game back from a shoulder injury, while Jade Gresham (22 disposals, three goals) was also dangerous in attack.
Saints ball-winners Jack Sinclair (33 disposals), Nasiah Wanganeen-Milera (27), Seb Ross (25) and ruckman Rowan Marshall (25) were all busy.
Jayden Short (26 touches), Dustin Martin (25) and Tim Taranto (24) were Richmond's chief possession winners, while Jacob Bauer and Liam Baker kicked two goals each.
King booted two of St Kilda's five goals in both the first and second quarters as Richmond's pressure game went missing.
The Tigers laid just 20 tackles to the Saints' 36 in the opening half.
There was a scare when Daniel Rioli was helped from the field during the second quarter after rolling his right ankle while attempting to change direction.
Rioli returned after the main break but did not have a huge impact.
He wasn't alone in a Tigers side that was comprehensively outplayed.
The Saints led 10.2 to 5.3 at halftime and while scoring slowed in the third quarter, the home side still managed to increase its advantage to 43 points by the final change.
Richmond won the final stanza - 2.4 to 1.3 - when the sting had gone out of the contest.
St Kilda forward Tim Membrey was goalless from 15 disposals on return from a knee injury but got through unscathed in his first game since round nine.
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