Team Sky’s Welsh star will lead the 132-strong field for the four-day race, which starts on Thursday in Koblenz, in his first stage race since completing his stunning victory in Paris last month.
Thomas’s presence will boost the profile of the Tour of Germany, which is back on the cycling calendar after a 10-year hiatus.
“I’ve won Bayern-Rundfahrt [Tour of Bavaria] twice and I really enjoy racing in Germany,” said the 32-year-old Welshman.
“It’s a lovely country and I really enjoy going there.
“It will be great to race the Deutschland Tour. I went to see my coach Tim Kerrison after the Tour and we outlined the Deutschland Tour as a great race to make my comeback. I’m looking forward to it.”
Thomas has good memories of racing in Germany.
He was fastest in the opening individual time trial in Duesseldorf when the 2017 Tour de France started in Germany and he won the Tour of Bavaria in both 2011 and 2014.
The rest of this year’s Tour of Germany field will be announced on Monday, but the presence of Thomas is a big coup for race organizers.
“The best German young riders will ride together with the winner of the Tour de France. This only happens at the Tour of Germany,” said organizer Claude Rach.
“This is a dream debut for the new Deutschland Tour. During the four days, we will create Germany’s biggest natural stadium.”
The Tour of Germany is being held for the first time since organizers canceled the 2009 race after a series of high-profile doping cases damaged cycling’s reputation.
It was traditionally a nine-day event, but organizers hope to extend it in the future.
Thomas and Chris Froome, a four-time Tour de France winner, announced on Thursday that they will compete in next month’s Tour of Britain rather than the final Grand Tour of the season, the Vuelta a España.