It comes after Welsh cycling veteran Colin Lewis said “doors have now opened” for the race to come to Wales following Thomas’ emphatic Tour win.
The Welsh Government have been in talks with Tour de France and Giro d’Italia bosses as they consider a bid to host stages of the Grand Tour races.
Team Sky rider Thomas said a Welsh leg of the Tour would be “amazing”.
“I’ve heard some rumours about that and it would be great if they could pull it off for sure,” said double Olympic champion Thomas.
“Hopefully it can happen.”
Thomas made history by becoming the first ever Welshman to win the Tour de France after holding his stage 12 lead all the way to Paris.
The 32-year-old, who is also the third British rider to win the event, said the events of the past few days had been pretty surreal.
Thomas said he hopes to be back in Wales next week.
While plans of a “homecoming” parade have been discussed in his home city of Cardiff, the former Whitchurch High School pupil said any kind of reception “would be nice”.
“Just seeing the support on Twitter I’ve had has been incredible,” said Thomas.
“I’m obviously looking forward at going back home to Cardiff some point next week.
“It’ll be really nice to see friends, family and enjoy it all.”
Among those toasting Thomas’ triumph is Colin Lewis, who was the first Welshman to finish the gruelling three-week race in both 1967 and 1968.
He said: “As many English-speaking riders as French take part now, so more doors have opened.
“It would be expensive to get a start in Cardiff, but it is such a prestigious event and could attract thousands.”
The 76-year-old said there could also be “a knock on effect”, with the exposure from Thomas’ win getting more youngsters interested in the sport – which could produce future Welsh winners in the process.
Mr Lewis said things had changed since the Tour de France first crossed the channel in 1974 – calling the Plymouth stage “a disaster”.
He said: “It was the first time out of France and the pros didn’t like it.”
However, since then it has successfully been hosted in a number of overseas cities – including Portsmouth (1994), Dublin (1998) and London (2014).
The first stage of the 2018 Tour of Britain will start in Wales in Carmarthenshire.
Culture secretary Dafydd Elis-Thomas said the Welsh Government was “always on the lookout” for major events.
“There will be an opportunity for further cycle races, there’s been a discussion about the Giro d’Italia and I’ve been part of some of those discussions so we are hoping that we will be able to attract these events,” he added.
“It’s expensive to hold these events but whatever benefits from the legacy of what Geraint has already achieved, the key thing is the message it gives to every individual in Wales is that you’ve got to be active.”