Tommy Smith, Jonathan Hogg and Rajiv van La Parra have all signed extensions to 2020 with the club having an option to extend the deals by a further 12 months.
The trio committing their futures to Huddersfield follows similar deals for Chris Lowe and Elias Kachunga last week.
Head Coach David Wagner said: “In addition to the news of extensions for Chris Löwe and Elias Kachunga last week, the new contracts for Tommy, ‘Hoggy’ and Rajiv are very important pieces of business for this club.
“Tommy had a standout season last year and full deserved the recognition he received from his place in the (PFA Championship) Team of the Year.
“I said to him very early into my time here that I believed he could be one of the best right backs in the Championship and he achieved this through hard work on the training pitch every day.
“He is a big figure in the dressing room, too. He was a superb leader for us on and off the pitch last season.
“Everyone knows I love ‘Hoggy’, too. He is the player that embodies our ‘Terriers Identity’ more than any other and I know he will relish the challenge of showing this against the top-quality midfielders of the Premier League this season.
“He is another huge character in the dressing room and his winning mentality is exactly what we need as we face a new challenge.
“Rajiv is such an exciting talent and I fully believe that he still has a big space to improve, which is great considering what a threat he is for us on the pitch already.
“Last season, we were a better team when Rajiv was playing. He can cause the opposition problems and is a big asset in our transitional play. I’m looking forward to seeing how he adapts to the Premier League challenge, too.
“All three players were so important to the team last season; they have shown they are great Championship players. Now they have to prove they can do it in the Premier League. This is the next step for them and the next step in our journey.”