The 44-year-old German has agreed to succeed Unai Emery, who will leave the Qatar-owned side after the final game of the French season this weekend.
“It is with much joy, pride and ambition that I am joining this big club,” said Tuchel in a statement released by PSG.
“I can’t wait to start working with all these great players who are all amongst the best in the world.
“Paris Saint-Germain has enormous potential and it is by far the most exciting proposition in football.”
According to French sports daily L’Equipe, Tuchel was recommended directly to Qatar’s Emir Sheikh Tamim bin Hamad Al-Thani by the Qatari consul in Germany.
At one point linked to Arsenal before Arsene Wenger announced he would be leaving the Premier League club, Tuchel will begin his new role in early July with the start of pre-season training.
It was an open secret that Tuchel had been lined up as the next coach of the ambitious club from the French capital.
Paris Saint-Germain are delighted to announce that Thomas Tuchel will be the new first-team coach next season !
The German tactician has signed a two year contract with the French champions 🔴🔵 pic.twitter.com/JoeU0jMqFC
— Paris Saint-Germain (@PSG_English) May 14, 2018
They had been on the look-out for a replacement for Emery since being beaten 5-2 on aggregate by Real Madrid in the last 16 of the Champions League in March.
That disappointment in Europe, following a humiliating loss against Barcelona at the same stage a year ago, meant there was no chance of Emery’s two-year contract being renewed at the end of this campaign.
Emery has nevertheless just overseen a clean sweep of the domestic honours in France this season, after winning the French Cup, League Cup and season-opening Champions Trophy in his first campaign.
Tuchel was a free agent after leaving Borussia Dortmund a year ago, despite leading the team to victory in last season’s German Cup.
“Thomas is one of the best and most competitive European coaches to have emerged over the last few seasons,” declared PSG president Nasser Al-Khelaifi.
“He abides by very strong principles of playing spectacular and clinical football that has always been the foundation of German football, especially on the international scene.
“His competitive spirit, his preference for attacking football and his strong character are in line with what we have always wanted for Paris Saint-Germain.”
Neymar has been linked with a return to La Liga as Real Madrid have been the rumoured destination.
Watch Al Khelaifi shut down those rumours in the video below, in which he says “Neymar is staying 2,000 per cent, he has not informed me of his intentions to leave”.
The Brazil international has been heavily linked in the media with a possible move to Real Madrid this summer, just a year after leaving their bitter rivals Barcelona for France in a world-record transfer.
However, Al-Khelaifi is confident the 26-year-old striker will be a Parc des Princes fixture for the foreseeable future.
Asked whether Neymar will be at PSG next season, Al-Khelaifi said in quotes reported by Le Parisien: “For me, for Neymar, I am 2,000 per cent sure he will stay.
“He wants to stay here, he has a contract.
“The Spanish media have been talking since October. He is not happy, this, that…All that is wrong. I don’t respond to rumours.
“I’m sure he’ll stay, he’s a Paris St Germain player.”
Neymar joined PSG in a £200.8m transfer last August and scored 28 goals in all competitions before suffering a broken metatarsal in February which has kept him sidelined since.