Six of the team - McIlroy, Kaymer, Fisher, Hanson and both Molinaris - will all be making their Ryder Cup debuts at Celtic Manor from 1-3 October.
Montgomerie claimed Molinari "probably didn't need to win" in Perthshire to earn a pick, however, he heaped lavish praise on the 2009 World Cup winner after he birdied his last three holes to snatch a one-shot victory from Australian Brett Rumford.
"In my time as a player on the European Tour, and I've been a member for 24 years, I don't think I've seen a finish of that quality under pressure by anyone anywhere," said Montgomerie.
"I think what he did today was, literally, incredible and he is the type of player we need to regain the Ryder Cup from America."
The Molinaris, who won the World Cup together in China last year, will become the first siblings to play in the Ryder Cup since Bernard and Geoff Hunt played for Britain in their 1963 defeat against the USA.
It was quite an emotional moment for me because this means I will be playing with my brother and that is something that is almost unreal
"It's a delight that we have two thrilling players coming from an emerging country like Italy and it's no secret as to who will be partnering each other at Celtic Manor," Montgomerie said.
Edoardo Molinari, who was playing on Europe's second-tier Challenge Tour last season, said: "I would have been happy a year ago to have enough money to keep my card by this time.
"Colin told me he was proud of what I had done and I said 'thank you very much and I can't wait to get to Wales.'
"It was quite an emotional moment for me because this means I will be playing with my brother and that is something that is almost unreal."
Edoardo's inclusion was bad news for Englishmen Casey and Rose, both competing in the final round of The Barclays, the first event of the four-round FedEx Cup, in New Jersey.
Montgomerie revealed he had informed Rose, a two-time winner on the US Tour this season, of his decision as he prepared on the range ahead of his final round in New Jersey. Rose will, though, be selected if Westwood fails to recover from an ongoing calf injury.
Montgomerie admitted he felt sorry for world number nine Casey and Rose, a two-time winner in the US this year, but said Europe "had an embarrassment of riches on this occasion".
"Padraig has won three majors in the past two years, he has great stature in the game and when his back is up against the wall he comes out and gives tremendous," said Montgomerie.
"He is someone we felt that nobody in matchplay golf wants to play. He's a great competitor.
"In Luke Donald we have someone who can compete in foursomes and fourball golf, and has played seven Ryder Cup games and only lost once."
Dubliner Harrington, who has not won a game in the last two Ryder Cups and not won a Tour title since the USPGA Championship in 2008, said: "It was obviously experience as the team is a young team. I won't normally play the age card, but this time it obviously suits me.
"It's tough on the two boys and it was an odd occasion. On one hand I'm happy for myself, but I did genuinely feel sorry for Paul.
EUROPEAN RYDER CUP TEAM
Lee Westwood (Eng) Age 37; Previous Ryder Cups 6
Martin Kaymer (Ger) 25; Debut
Rory McIlroy (NI) 21; Debut
Graeme McDowell (NI) 31; RC 1
Ian Poulter (Eng) 34; RC 2
Ross Fisher (Eng) 29; Debut
Francesco Molinari (Ita) 27; Debut
M A Jimenez (Spa) 46; RC 3
Peter Hanson (Swe) 32; Debut
Padraig Harrington (Ire) 38; RC 5
Luke Donald (Eng) 32; RC 2
Edoardo Molinari (Ita) 29; Debut
"I commiserated with him. It's not a nice place to be. But there's no doubt myself and Paul, Justin and Luke didn't play enough in Europe to make it on the team automatically."
England's Donald, who missed out in 2008 with a wrist injury, found out he was in the team after he had finished playing the 10th hole in the Barclays event.
"My caddie said, 'Good news, we're in', so obviously there's a lot of relief," said Donald. "There were some anxious moments in the last few days."
Montgomerie also named out-of-form Spaniard Sergio Garcia, who has played in every Ryder Cup since 1999, as his fourth vice-captain alongside Paul McGinley, Darren Clarke and Thomas Bjorn.
"He said 'let me have a role', which shows what the Ryder Cup means to him and he is going to be a great asset to us," Montgomerie said.
Jimenez, 46, missed his nephew's wedding to defend his position in the last automatic qualifying spot at Gleneagles.
He needed to finish in the top nine to make sure of a fourth Ryder Cup cap and finished joint third after double bogeying the short 17th, while Hanson, who was eighth in the standings, required a top-43 finish and was 19th.
"It means a lot. It's very important to me and I'm glad to be part of the team again," said Jimenez, who becomes the oldest European player.
Hanson, who won last week's Czech Open to leap from 15th on the points table, shot 72 and said: "I was very tired coming here and I've been battling trying not to think about making the team.
"I think I'm going to celebrate tonight - and tomorrow as well."
Montgomerie has invited Welshman Rhys Davies to accompany the team when they take on the United States.
"I felt it was important to have some Welsh representation on the course," said Montgomerie. "I think he's a Ryder Cup player of the very near future."
Davies, 25, has enjoyed a successful rookie season on the European Tour, securing five top three finishes and winning March's Hassan II Championship in Morocco.
The eight automatic qualifiers on the US team are Phil Mickelson, Hunter Mahan, Bubba Watson, Jim Furyk, Steve Stricker, Dustin Johnson, Jeff Overton and Matt Kuchar.
Captain Corey Pavin is set to add his four wildcards on 7 September, with world number one Tiger Woods among those hoping for a pick.
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