The capture of the talented tighthead gives Director of Rugby Phil Davies more front row options ahead of next season. The Blues yesterday announced the signing of Samoan international centre Isaia Tuifua and plan more new arrivals moving forwards.
A destructive scurmmager but also mobile around the park, Mitchell captained Wales at Under 19 level and quickly rose up the ranks to the senior international set-up. He made his full Wales debut on the summer tour of North America and Canada in 2009 and played in both the 2011 and 2013 Six Nations. He scored his first senior international try against Ireland at the Millennium Stadium in February of last year.
Davies said: "Craig is an experienced player and he's clearly learnt a lot during his time with Exeter. He's delighted about this opportunity with Blues and we are very excited a player of his quality and calibre will join us.
"Craig is known for being an exceptional set piece player but his work rate and impact outside the scrum is also very good. He complements the props we have and the front row will be much stronger for his signing.
"With a World Cup just around the corner, we are delighted an international quality player of his experience is coming back to Wales determined to make an impression for us.
"I have spoken to Craig at length about what we expect from him and he's coming here keen to play a big part in the future of the Blues."
Mitchell said: "I'm really pleased that the opportunity has come up at the Blues and I'm looking forward to coming back with my family for a fresh challenge.
"I've been at Exeter for three years and it's been an experience that I feel has really benefitted me. The club and coaches have been great, but now feels like the right time to come back home.
"Phil has spoken to me about the plans at the Blues, the make-up of the squad he is looking to build and I have watched them play this season. They are looking to play an exciting brand of rugby and I'm keen to get my head down, work hard and be part of what I am sure will be an exciting future."