The Suns called time on Sheedy's storied coaching career, streaking to a 22.14 (146) to 9.9 (63) win to post their eighth victory of a breakthrough campaign.
The winning margin is the biggest in the Suns' three AFL seasons, eclipsing their 60-point win over Melbourne at the MCG earlier this year.
Defeat means Sheedy's 679-game coaching career, which included four premierships during his time with Essendon, ends with just one win in 2013 and this year's wooden spoon.
Suns captain Gary Ablett, chasing three votes to enhance his bid for a second Brownlow medal, led the way with four goals and 33 disposals.
Andrew Boston also had four goals for the hosts with Danny Stanley (three) and Jarrod Harbrow, Michael Rischitelli and Harley Bennell (two) the other multiple-goalkickers.
Jeremy Cameron could only manage two goals for the Giants, ending the year on 62 overall to finish six behind Hawthorn's Jarryd Roughead in the Coleman Medal chase.
GOLD COAST SUNS 6.1 12.3 16.7 22.14 (146)
GREATER WESTERN SYDNEY GIANTS 2.4 5.4 7.8 9.9 (63)
Goals: Gold Coast Suns - Boston, Ablett 4; Stanley 3; Bennell, Harbrow, Rischitelli 2; Hall, Dixon, Prestia, Gillbee, Hunt. GWS Giants - Cameron 2; Kennedy, Tomlinson, Hampton, Giles, Sumner, Coniglio, Adams.
Best: Gold Coast Suns - Ablett, Prestia, Boston, Rischitelli, Stanley, Weller. GWS Giants - Tomlinson, Adams, Coniglio, Giles.
Umpires: Robert Findlay, Andrew Mitchell, Matthew Leppard.
Official Crowd: 13,080 at Gold Coast Stadium.