Doull, 23, joined Sir Bradley Wiggins' outfit in January 2015, but will now link up with compatriots Geraint Thomas and Luke Rowe at Team Sky.
The Cardiff-born cyclist is aiming to be part of Great Britain's team pursuit squad at Rio 2016.
"I grew up watching what he [Thomas] did in Beijing [2008 Olympics] in the team pursuit," said Doull.
"Hopefully that [winning gold] is something I can replicate in Rio.
"It's not just Geraint. Luke is starting to achieve in the classics and younger guys like Scott Davies are coming through as well.
"It's an exciting time for cycling in Wales."
Team Sky boss Sir Dave Brailsford said: "I think it's pretty self-explanatory why we wanted Owain at Team Sky.
"He has consistently put in excellent performances on the track and the road for a while now and we think he has the potential to be an important part of the team.
"From a personal perspective it's always great to be bringing young British talent into Team Sky and it reflects very well on the investment and support Sky has provided through the British Cycling programme, the Wiggins team and, of course, Team Sky.
"The fact that Owain is another addition to our Welsh contingent is obviously another big positive.
"Owain has a big year ahead of him with the Wiggins team and then the Olympics, but we're looking forward to giving him a proper welcome to Team Sky after Rio."
Welsh cyclist and Rio Olympics hopeful Owain Doull will join Team Sky next season from Team Wiggins.