Mark Lancaster has joined fellow Tory candidate Iain Stewart to retain his seat in Westminster.
Mr Lancaster had a majority of 1,915 against Labour candidate Charlynne Pullen.
The remarkably reduced majority was announced just minutes ago, with a total of 30,307 votes for Mr Lancaster and 28,392 votes for Labour candidate Ms Pullen.
The Liberal Democrat candidate Imogen Shepherd-DuBey received 2,499 votes, Green candidate Alan Francis received 1,107 votes and UKIP candidate Jeff Wyatt received 1,390 votes.
Mr Lancaster paid tribute to former MP Brian White, who died last year, and said Milton Keynes needs to come together to ensure the best for everyone.
He said: "There's one face not in the audience tonight, and if he would have been, he would have had a wry smile on his face. That man is Brian White. Not seeing him here for my fourth election is odd, and he was very gracious in defeat to me in 2005.
"I'm deeply honoured to have been elected for the fourth time, with a reduced majority, but it is bigger than I first had. It has been an unpredictable election.
"I would like to thank my fellow candidates - it has been thoroughly enjoyable and fair.
"We need to move forward and unify as Milton Keynes because the issues as a city and a country now we move towards Brexit means we have to come together. That's actually something we're very good at in Milton Keynes, and I look forward to working with everyone in the coming years to ensure we get the best deal for the UK and indeed MK."
Mr Lancaster's majority was significantly cut by Labour candidate Charlynne Pullen, who said: "I'm not sure any of us expected this result, it's fantastic for us and it's a tribute to the positivity of the Labour campaign, manifesto and the campaigning we've done. I'll assure we won't stop doing it, and I hope to see you all again.