A former NZ schools representative, Gregory is an outside back who has also played Sevens for New Zealand.
Gregory made his first-class debut for Northland last year, played 10 games and scored two tries. He played for the NZ Colts side in 2018 in France and backed that up with another stint for the colts at the world junior championship in Argentina.
A former NZ age grade athletics champion, Gregory was a member of the All Blacks Sevens team this season, playing in several tournaments throughout the year.
In a statement, Gregory said he was pleased to be heading south.
``I'm thrilled to be given an opportunity to head down south to the Highlanders for the coming season. All part of a childhood dream,'' he said.
He has signed a two-year deal with the Highlanders.
He will replace the likes of wingers Waisake Naholo and Tevita Li, who have left the Highlanders to play overseas. Gregory can also play in other areas of the backline.