Two weeks after the rumour of his departure first surfaced, Hoeata and the club have struck a three-year deal.
''I wanted to leave New Zealand while I am still on top of my game so I could really contribute wherever I went,'' he said.
''I am now really excited about joining Cardiff Blues and helping them reach some lofty goals. I have only heard positive things about the Blues set-up and Cardiff itself.
''I am good mates with Paul Tito, who thoroughly enjoyed his time there, so I am really looking forward to the move once I'm finished with the Highlanders.
''I'm excited about the challenge of playing rugby in Europe. I am sad to leave New Zealand but at the same time, I'm extremely proud of what I've achieved.''
Hoeata (30) is in his fourth year with the Highlanders, having formed a key part of coach Jamie Joseph's first squad in 2011.
That was the year he reached the pinnacle of rugby, All Black selection, and earned three test caps.
He has also played for the Maori All Blacks, and been a long-serving contributor for Taranaki.
''I have really loved my time down south with the Highlanders,'' Hoeata said.
''I'd like to thank Jamie Joseph for the massive opportunity he gave me to initially be a part of the Maori All Blacks in 2010, and then offering me an opportunity to head down and join the Highlanders.
''With the help of Jamie and the boys managed to reach my ultimate goal of becoming an All Black.''
With Hoeata gone, Josh Bekhuis also coming off contract and Brad Thorn rising 40, it seems likely the Highlanders will look for another locking option.
