Eighth seed Swiatek showed off her grass-court improvements as she won 6-2 7-5 on Court One.
Samsonova threatened a fightback as she rallied in the second set, but four-time French Open champion Swiatek dug deep to progress.
“It feels great, I have goosebumps after this win,” said Swiatek.
“I am super happy and super proud of myself and I will keep going.
“I really enjoy playing (on grass) this year and hopefully it is going to last as long as possible. I worked hard to progress here on this surface.”
Swiatek had won all four previous meetings against Samsonova, but this was their first on grass, which has been the least successful surface of Swiatek’s career.
However, she made her first grass final ahead of Wimbledon and has impressed over the last 10 days.
“This year I feel like I developed as a player, and I had time to practice little bit more,” said Swiatek.
“Match by match my confidence, for sure, went up so that I can use it on this championship.”
Samsonova had not lost a set on her way to a first Grand Slam quarter-final and had a break point in the opening game, but Swiatek saved it with an ace.
The former world No. 1 soon started to find her range, rattling through a quick hold and then breaking after excellent defence won her a point.
Samsonova vented her frustration towards her box after the game and her mood didn’t improve as she whacked a forehand long to hand Swiatek the set.
Samsonova made 18 unforced errors in the opening set and back-to-back double faults handed Swiatek another break early in the second set.
Just as the match looked to be getting away from Samsonova, she had four chances to break back in the third game.
Although she couldn’t take any of them, she did take the next opportunity when Swiatek fired wide in her following service game.
But another double fault gave Swiatek a 4-2 lead as the Pole seemed to be closing on victory.
Samsonova, though, was not done, breaking straight back and getting on level terms.
The Russian started to take charge of more points with her powerful hitting as Swiatek had to dig deep to hold from 0-30 in the 11th game.
That hold proved crucial as Swiatek broke in the next game to seal victory, clinching it with a forehand winner.
