Coote, who was born in Windsor, NSW, will end an illustrious 15-year career after winning a host of trophies in Australia and England.
The 33-year-old played for the Penrith Panthers in the NRL, and was a member of the North Queensland Cowboys' 2015 premiership and 2016 World Club Challenge-winning sides.
He then won three consecutive Super League grand finals after he signed for St Helens in 2019, before moving to Hull KR last season.
He was capped by Scotland and Great Britain.
"I'm happy to announce that I will be retiring at the end of the 2023 season,"Â Coote, who will miss the next month with a hamstring injury, said.
"It has been a very tough decision to make but I know it's the right one for me and my family.
"There will be plenty of time to reflect on my career at the end of the season. There's still a long way to go this season, I'll be looking to make the most of every moment and finish this year with a trophy."
Hull KR head coach Willie Peters added: "Lachlan is a proven winner and a quality person.
"His professionalism and leadership qualities are right up there with the best. I have no doubt whatever Lachlan decides to do post-rugby, it will be a success."
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