Ross' haul included seven three-pointers as he repeatedly bounced open off screens and ensured the Bombers' season ended with a whimper.
St Kilda saved its best offensive performance for last, shooting 13 from 27 from deep and completely outclassing the Bombers in the process.
Tom Ingham struck three times from deep as he scorched the Bombers for 20 points, while Tom Tindale (15 points) had a stellar game inside.
The big centre was devastating going to the hoop, often drawing crucial fouls from hapless Bombers defenders. Saints coach Simon Clarke said it felt good to win the title after falling to Magic A at the last hurdle a season ago.
''It's been a really enjoyable year. The boys learned a lot from the final last year. We grew a lot as a team and trusted each other more.
''Jimmy [Ross] was fantastic. He was obviously the difference. He's been the best player all season.''
Ross' 30-point barrage pushed his season total to a league-high 296 points and probably cemented the MVP award.
Clarke also praised Tindale and his team's defensive effort after forcing the Bombers into 27 turnovers, the majority of them after the Saints unleashed their full-court defence.
''It's a tough match-up for anyone when Tom is dominating inside and the outside guys are making shots.
''The shooting and inside presence is good, but really it starts at the defensive end for us. Getting steals, which lead to easy baskets.''
After four tight games between the sides before the final, the Saints cruised out to a 29-12 first quarter lead on the back of 10 Bombers turnovers.
It blew out to 42-26 at halftime, before the Bombers rallied early in the third quarter to get within 12. However, Ingham, Ross and Tindale only needed three minutes to put the Saints back up by 21 and the Bombers never threatened again. No Bombers player scored double figures and they shot a woeful two from 20 from three-point land.
Bombers coach Mike Simpson said he was gutted to lose the final but was pleased with how the season went overall.
''We just couldn't get our offence going and we turned the ball over too much. We knew they were going to put the full-court pressure on us and I think we did quite well against it in the first half. But we couldn't stop James Ross.
''I thought we did as well as the Saints defensively but we weren't as good offensively.''
Ross, St Kilda's captain, said basketball was a simple game when shots were dropping and credited his side's defensive attitude.
''It was just one of those occasions when everything came together. We hadn't shot well the last few weeks. But when Tom [Ingham] is making shots, when Stanley [Williams] made a couple of big threes at the end ... I was lucky to hit a few.
''Defence is something we pride ourselves on, playing really intense, hard, full-court man defence.''
St Kilda has won the men's A grade competition every second year since 2008 and has 15 titles since 1991.
By Robert Van Royen.
