McGillvary, whose 27 tries this term could see him named in Steve McNamara’s England squad on Sunday for the New Zealand Test series, will now stay at the West Yorkshire club until the end of 2020.
He has scored 101 in 148 games during his Huddersfield career and admits he was never likely to leave his hometown club despite that interest.
Giants missed out on the Grand Final when losing at Wigan last Thursday but McGillvary – named in Super League’s Dream Team for the first time last week – said: “I’m happy at Huddersfield, always have been and imagine I always will be. The supporters are always great to me and I hope I can keep playing and improving to give them some success.
“This season has definitely been my best so far and I wanted it to keep going but we let ourselves down at Wigan.
“I’m not sure about my plans for the off-season yet as I’m hoping for an England call.
“But whatever happens I know I’m a Giant for a long time now we’ve make sure we are all better next year and can again challenge for trophies.” Huddersfield head coach Paul Anderson added: “Everyone knew that Jerry was a good player.
“My challenge to him at the start of the year was to show he is a very, very good player and one who should be asking questions of selection into the national team.
“The only way to do that is through consistently high form and everyone can see that’s exactly what the lad has produced.
“He has finished his year as Super League’s top try-scorer and is right up there for his metres gained which is a huge part of his armoury.
“Every winger will tell you he needs quality inside him and Jerry’s got that here which being the type of lad he is he is always the first to say.
“He’s a Huddersfield boy and that’s important to us too and demonstrates to the game that our local area produces talent which gets its rewards and obviously everyone knows he is a fans’ favourite.”