Jonathan Sexton signed off before the Lions tour with 14 points as his home province were crowned champions for the first time since 2008, ending a run of three successive league final losses.
New Zealander Schmidt, who will take over the Ireland job later this year, bowed out with a much-prized domestic and European double - eight days on from his side's Amlin Challenge Cup success.
A resilient Ulster certainly put it up to them in this all-Irish decider, with their South African star Ruan Pienaar kicking immaculately in an 18-point haul.
But tries in each half from back rowers Shane Jennings and Jamie Heaslip, allied to some rock solid defending, got Leinster over the finish line.
Sexton booted three penalties after converting Jennings' early try as Leinster - without late withdrawal Rob Kearney, who had a tight hamstring - ended a hugely physical first half with a 16-6 lead.
Despite leaking a succession of penalties, particularly at the breakdown, the Ulstermen remained in the hunt thanks to Pienaar's opening two kicks.
The place-kicking battle continued after yellow cards for Robbie Diack and Isa Nacewa - in his final professional match - with Pienaar drawing Ulster back to within four points.
However, Heaslip's try entering the final quarter proved to be enough to seal it in favour of the men in blue.
Table toppers Ulster designated the RDS as their home venue for the league final - with Ravenhill not meeting the minimum 18,000-capacity mark - and they wryly renamed the Dublin venue 'OurDS'.
- Sports & Recreation
- Ruan Pienaar
- Jamie Heaslip
- Shane Jennings