The No 8 will link-up with Blues with immediate effect and bolster the back-row resources at Cardiff Arms Park – a venue where his father Steve also spent three seasons.
Moore, who was born in Cardiff but brought up in England, attended the prestigious Sedburgh School and represented the Red Rose at Under-16, 18 and 20 level.
He was also a member of Eddie Jones’ senior England Six Nations squad in 2018 as an apprentice but will return to Wales after penning a long-term deal in the capital.
Standing at 6ft 6in and tipping the scales at more than 17 stone, the former Everton academy footballer not only packs a punch physically but is athletic and skilful.
Cardiff Blues head coach John Mulvihill said: “We’re delighted to sign Sam. He is a player with enormous potential and it is great to get him here straight away.
“The fact England named him in their 2018 Six Nations squad is testament to that potential and we are confident he can realise it at Cardiff Blues.
“No 8 is a position we needed to strengthen and Sam will bring a big, physical and athletic presence. He has all of the attributes necessary and has a huge appetite to succeed.
“The pack is a focus for us as we look to strengthen our squad and securing the services of Sam is just the first step in doing that.
“We are all looking forward to getting him on the pitch in a Blues jersey as we fight to reach the play-offs in the second half of the season.”
Wales head coach Wayne Pivac said: “It’s great to see another Welsh player joining one of the Welsh regions from across the bridge. Sam is a big, athletic man with a big future in the game.”
Moore is currently sidelined but is expected to be fit and firing within a matter of weeks and is relishing the opportunity to take his career to the next level at Cardiff Blues.
He said: “I’m really pleased to be joining Cardiff Blues. I have been really impressed by the vision they presented to me, what they are currently developing, and their long-term plans for success.
“Having met Richard Holland and Alun Jones and spoken at length to the coaches at both the Blues and Wales, I am convinced this is the best place for me to progress my career.
“I am eternally grateful to Sale Sharks who gave me my first opportunity. I have been in their system since I was 14 and have a huge amount of friends there. I wish them the very best for the future.
“But I was born in Cardiff and my Dad played here in the 90’s so it is a place close to my heart and I cannot wait to get started at the Arms Park.
“While I grew up in England and came through the system there, I view myself as a Welshman and it would be great to reach the same heights as my dad and uncle, but I am well aware that it all starts with the Blues and that is my sole focus.
“There is already a lot of competition in the back-row with the likes of Josh Navidi, Ellis Jenkins, Nick Williams, Will Boyde and Olly Robinson to name just a few. I am just looking forward to getting back on the pitch, showing what I can do, and contributing to this exciting team.”
