Set 270 runs to win, Jason Sangha and Alex Carey scored centuries as SA posted 6-270 for a drought-breaking victory on day four of the decider in Adelaide.
SA's feat is the highest successful run chase in a Shield final, eclipsing Victoria's 2-239 against NSW in 1990/91.
And the South Australians now hold the Shield and the one-day trophy in the same season for the first time, having downed Victoria in the 50-over final on March 1.
On Saturday, Sangha and Carey produced a brilliant 202-run partnership after SA stumbled to 3-28 at Karen Rolton Oval.
Sangha, in his first season since leaving NSW, scored a classy unbeaten 126 and Carey - one of only two South Australian-born players in the Shield champion team, with Conor McInerney - struck a superb 105.
Their match-winning union followed earlier heroics from SA paceman Brendan Doggett, who returned the best-ever match figures in a Shield final.
Doggett, a former Queenslander, took 11-140 including 6-31 when the Bulls were skittled for 95 in their first innings - the lowest total of any state batting first in a Shield decider.
SA, powered by Jake Lehmann's 102, replied with 271 all out.
Queensland appeared down and out when 6-221, just 45 runs ahead, in their second innings at lunch on day three.
But tons from Jack Wildermuth (111) and Jack Clayton (100) triggered a revival and the visitors made 445, a 269-run lead.
That target seemed secure when SA lost three wickets inside the first hour of Saturday's play.
And it could have worse for the success-starved hosts: Sangha, on 13 and the score 3-37, was dropped by Ben McDermott at second slip from the bowling of Mark Steketee (3-40).
The elegant right-hander then flourished, reaching his century from 158 balls and hitting 16 fours and two sixes overall.
Two overs later, Carey saluted an increasingly raucous home crowd on completing his fourth ton in five Shield matches this season.
Carey's stellar 132-ball knock ended soon after when bowled by a Steketee slower ball with 40 runs still required for victory.
First-innings century-maker Lehmann, the son of SA great Darren Lehmann who played in the state's last Shield triumph in 1995/95, was bowled for eight, and Liam Scott was dismissed for a duck.
That left Sangha, fittingly, to score the winning runs through midwicket with a stroke that instantly entered SA sporting folklore.
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