The Lions’ star on-baller was rewarded for his dominant season on the field when he claimed the Morrison Medal on 22 votes.
O'Sullivan, 23, was a runaway victor in the senior football count that was held virtually due to COVID-19 restrictions.
In the shortened 11-game season, O'Sullivan polled 22 votes — seven more than his closest challenger Zac Keogh (15) from Kyabram.
O'Sullivan, a former VFL-listed talent, credited his strong season to his teammates.
“I definitely was not expecting it to be honest, but it is nice to be recognised,” O'Sullivan said after the vote count.
“I truly do believe that any individual award is a reflection on the team and your teammates around you. I have to thank the entire coaching staff, they have been fantastic, my teammates and my parents. I'm sure there are many more people who I have missed.”
O'Sullivan enjoyed an eye-catching campaign.
The silky midfielder claimed five best-on performances and there was only two games where he didn't poll votes from the umpires.
Quite the outstanding feat for a player enjoying his first season at Kings Park.
Seymour coach Ben Davey was thrilled that O'Sullivan's sublime year culminated in a league best-and-fairest award.
“I'm very happy for him, the whole club is rapt for him,” Davey said.
“He is such a lovely and likeable fella; it's impossible not to like him. The way he spoke (on Tuesday) says a lot about him and his character.
“Although it's true to an extent (his performances being a beneficiary of the players around him), there are no doubts his talent and hard work got him that medal. He played so well and to not poll a vote in only two games out of 11 shows just how well he played.”
It was the first time in 17 years — and only the fifth time in history — that the Morrison Medal was claimed by a Seymour talent.
The last Seymour footballer to claim the title was Shane Schottner in 2004.
Davey highlighted the significance of O'Sullivan taking out the honour.
“Him winning the Morrison Medal means so much to the club,” he said.
“Jack is such a great role model. What he brings to the club, with his work ethic and experience is just outstanding.
“All the younger guys see first-hand the amount of work he puts in and that is the most pleasing aspect of his win, that those juniors see that they can also be in that position if they put in the hard work.”
More local sport
Schache prepares for biggest game of his career
Shepparton United star takes out second Wellman Family Medal
Echuca export Ollie Wines takes out Brownlow Medal
11°C