The Czech world No. 7 did not drop a single service game as she secured the third clay-court title of her career and her first in Rome in one hour and 25 minutes.
British No. 1 Konta struggled to trouble Pliskova on serve as she fell to a seventh loss in eight meetings between the players.
The result means Pliskova will be the No. 2 seed at the French Open later this month after she moves to second place in the world rankings on Monday.
"I was a little bit nervous today, it's a final so you have to be. Jo played great tennis so she made it quite tough for me," Pliskova said.
Asked about her prospects at Roland Garros, she added: "I just hope I can take the tennis I was playing here to Paris and we'll see.
"I think there will be a chance for me if I play this way but there's going to be some tough opponents who are playing good tennis on clay."
Konta had beaten Grand Slam winners Sloane Stephens and Venus Williams as well as Madrid Open champion Kiki Bertens on her way to the final, but she was immediately under pressure as she was broken by the relentless Pliskova in her opening service game.
Konta was then forced to save a set point at 5-2 before Pliskova duly served out the first set after the Briton failed to take advantage of the only break point she was afforded in the match at 5-3.
Pliskova missed a break point in Konta's opening service game of the second set but eventually broke the 28-year-old at 3-3 before holding serve to secure victory.
Konta remained upbeat, saying: "I'm pleased with how I've been progressing this year and how I've been improving with every match.
"To make it to a final here, this is my second biggest final after Miami, this is a big moment for me."