The 37-year-old back-rower, who made the 400th appearance of his career in June, was in the Black and Whites team that won back-to-back Challenge Cups in 2016 and 2017 and is hoping to play in a first Grand Final before hanging up his boots.
The Sydney-born Italy international, who captained the Azzuri in the 2017 World Cup, played for Sydney Roosters, South Sydney and Gold Coast before moving to Super League in 2015 and has made more than 130 appearances for the Airlie Birds.
Minichiello said: “It was always going to be an extremely tough decision to make when you come towards the end of your career.
“I have enjoyed a fantastic 17-year playing career and my time here at Hull FC has been outstanding, so that made this decision so hard, but I guess that all good things have to come to an end at some stage.
“In future years, I want to be able to say that I finished my career at the right time. I still feel that I have a lot to offer to the team heading into the final few weeks of the season. And if I can come away with a Grand Final winners’ ring, then I will certainly be able to say that I retired at the right time.”
Hull coach Lee Radford said: “Mini has been an outstanding servant to the club.
“He has had a real influence on setting the culture at the club in recent years – the whole group will take away what he has brought long into their careers.
“He’s one of the greatest imports we’ve had during the Super League era.
“His level of consistency has been so high and still even at 37, he’s showing so much energy and desire.
“In time, he’ll be regarded as one of the great forwards to pull on a Black and White jersey.”