The 25-year-old forward, who has agreed a two-year deal with the Chiefs, joins from Championship side London Welsh and is the latest name added to the Exeter roster ahead of the 2014/15 season.
Just a week after confirming the arrival of prop Tomas Francis from London Scottish, Sydney-born Lees - who is equally at home in the second row or back-row - follows suit after weeks of speculation linking him with a switch to Sandy Park.
At 6ft 6in and almost 120kg, Lees is known as a hard running forward with an impressive turn of speed. He made his senior grade debut for Eastwood in 2010, having joined the club as a colt.
Lees would go on to make over 100 appearances for the club, including captaining them to Shield Shute success in 2011, with victory over Sydney University in the Grand Final, to end the club's eight-year wait for a shield title.
During his time Down Under, he was twice selected to represent Sydney in the annual fixture with GrainCorp NSW Country Gold Cockatoos in 2011 and 2012 - a game which showcases the best talent in the Shute Shield and NSW Country competitions.
Whilst his impressive performances also saw him selected for the ACT Brumbies A team in 2013.
Such talent did not go unnoticed and at the beginning of this year he was brought to England by Exiles coach Justin Burnell, who was keen to harness his qualities in helping Welsh regain their top flight status.
In an impressive season to date, Lees has helped play a key role for Welsh as they look to cement their place in the end-of-season play-offs and a potential return to the Premiership.
Having scouted Lees closely, Baxter has wasted little time in getting the player to agree terms with the Chiefs.
It's a move, which suits all parties, including Lees himself who said: "I’m really excited by the move, I’ve had a great season with London Welsh and really enjoyed my time there, but moving to the Chiefs is an opportunity I couldn’t turn down.
“This is only my second year as a professional player, so this move has come a lot earlier than I imagined it would have done. Exeter are a great club, one of the top sides in England, so to get the chance to come to play for them is a big thing for me.”
Like many outsiders, Lees has watched the rise of the Chiefs in recent years and he hopes he can now make an impact once he dons the club colours.
He added: "I was massively impressed with what I saw at the Chiefs and with the work being carried out at the complex, it’s only going to get even bigger and better. When I went down to speak to Rob [Baxter] he went through the history of the club and what they want to do moving forward. What struck me was the professionalism of the place - right across all the areas like the gym, the rehab, S&C, physios - it all seemed really switched on and was very impressive.
“Also the club and Rob are very ambitious about the future and as a player you always want to be involved in a set-up that is like that. No one really had to sell the club to me, their record over the last few years speaks for itself, and with the plans they have in place I think it will be a great place for me to play and hopefully develop my career even further.”
Testing himself in the Premiership is certainly going to be an experience for the young Aussie, but he admits he is more than ready to take on that challenge.
“The Premiership is well known throughout world rugby, it’s a tough environment for any player and the sides that compete in it each season are very strong," he continued. "Obviously Exeter have shown they can compete at the top end, not just in the Premiership, but also in the Heineken Cup as well.
“Some people have said that at times the physicality of the Championship is just the same as the Premiership, maybe even more at times, but it’s the pace and the skill level that make the real difference at the top end of the game. That’s something I know I will have to adapt to when I moved to Exeter, but I’m looking forward to the challenge of it all.”
