The 37-year-old half-back made his Super League debut for Halifax in 2002, but after two seasons there and a spell with Wakefield Trinity Wildcats in 2004, he spent a decade outside the top-flight – at Dewsbury and Featherstone Rovers – before returning to the elite competition in 2014.
He was a Challenge Cup finalist with Castleford Tigers in his first season there and later played for Wakefield and Widnes Vikings before dropping down a level to join Newcastle Thunder and finally Dewsbury.
Finn, who is also a former captain of the Ireland national side, will hang up his boots after Rams’ final game of the Championship season, at home to Oldham on Sunday.
“I feel as though I’m ready to finish now because this year has been the first time ever that I’ve lost a bit of the enjoyment you need to get the best out of yourself,” Finn said.
“The sacrifices you make to be a pro’ or semi-pro’ player started to outweigh my desire and I just knew I couldn’t give it my all anymore.”
Looking back on his three decades in the game, Finn reflected: “I’ve had a great time throughout the course of my career and made some good friends and I appreciate all the opportunities I’ve been given through the sport of rugby league.
“I’ve had some great times at most of the clubs I’ve been at and I think I’ve done a decent job in whatever role I had in any team.
“I’ve got no major plans for retirement, but I want to spend more time watching my kids play sports or whatever else they want to do and I think my partner Laura will appreciate having me around to help a bit more,” he added.
Rams coach Lee Greenwood hailed Finn as a “class act”.
He said: “To influence games in the way he has for such a long time speaks volumes of him as a player and as a person.
“He has been a credit to himself and his family throughout his long career and it is a pleasure for me to call him a good friend. He is exactly the player a coach would want as their number seven.”