However the 44-year-old German manager has signed a two-year deal in Paris, with the expectation of delivering the Champions League firmly on his shoulders.
"It is with much joy, pride and ambition that I am joining this big club, Paris St Germain", said Tuchel.
PSG says Tuchel signed a two-year contract with the French champions.
A statement from PSG declared Tuchel to be "a lover of dynamic, attacking football and an accomplished tactician", and that his Dortmund side was 'always adhering to his footballing principles based on teamwork, creativity, high intensity and competitiveness'.
"I can't wait to start working with all these great players who are all amongst the best in the world". With my staff, we will do everything to help the team succeed at the highest worldwide level.
Barcelona recovered from a 4-0 defeat at Parc des Princes to sensationally eliminate PSG 6-5 on aggregate last season.
"Paris St Germain has enormous potential and it is by so far the most exciting proposition in football".
The treble-winning Qatar-backed French club are seeking be an UEFA Champions League superpower, with a view to winning it, and Tuchel spoke of his readiness for the task ahead.
"I'm also looking forward to discovering the Parc des Princes, a legendary stadium of European football, where there is a fantastic atmosphere".
Following his impressive record in the Europa League with Sevilla, Emery was brought into Paris Saint-Germain in a bid to win the Champions League.
Club president Nasser al-Khelaifi was also quoted as saying on Sunday that Neymar would stay at PSG at "2,000 percent".