The former Wakefield prop, 27, has established himself as a regular this season under new coach Nathan Brown.
Griffin said: “I am very pleased we agreed a deal and as a result I look forward to three more good years. I have improved as a player under Nathan Brown and am sure that there is more to come from me and from the team.
“Obviously Wembley is going to be the highlight of my career so far and I am sure that with the way the club is strengthening and developing that we will have many more big games to look forward to.”
Coach Brown said: “Darrell is an improving player, he is someone that took a little bit of time to adjust to my coaching style but the past eight to ten weeks have been promising and he is a player that certainly still has some improvement in him.
“He has made some good contributions both on and off the field in the past few months and he looks after his body really well. Darrell has taken some really good steps in improving his game, which is pleasing as he is a big athletic guy who can definitely contribute to any team.”
Huddersfield travel to league leaders St Helens this weekend before their Wembley date with Warrington next week.