The 31-year-old will bring to an end an eleven-year association with the club.
MacArthur joined Glasgow in 2007 and signed his first professional contract with the club in 2009, making him one of Glasgow’s longest-serving players.
He joined the Centurion Club in 2014, starting an away victory over Benetton Rugby to make his 100th appearance for the Warriors. Only Graeme Morrison and Robert Harley lie ahead of the former Ayr man on the club's all-time appearance list.
The hooker has been part of some of the most famous moments in the club's history, including playing his part in the 2014/15 title-winning campaign, scoring his first try for the Warriors in a win over the Ospreys.
MacArthur was also part of the matchday squad that secured a first-ever European quarter-final for the club in 2016/17, coming off the bench in the historic 43-0 victory over Leicester Tigers at Welford Road.
The man from Irvine also earned six international caps during his career, making his debut for Scotland on the 2013 summer tour against Samoa, as well as helping Scotland 'A' record a 35-0 victory over England Saxons in 2012.
Speaking to Warriors TV following the announcement, MacArthur said: "It's been a hard decision, but I've had a great stint doing what I love. I believe it's the correct time for me to move on and transition into the next part of my life.
"I don't live too far from Scotstoun, so I hope to be able to come down and support the team. It'll be different sitting in the stands and not being able to do anything to help.
"I've continually looked at a double career path and now I'll hopefully have the opportunity to move into construction or project management after studying civil engineering at university, which will provide me with a different challenge.
"The things that stand out for me at Glasgow are the things the fans don't see. The camaraderie in the changing rooms, the feeling before a game when you shake hands. At that moment you know you're both about to go out onto the pitch and put your bodies on the line.
"Glasgow is a club which has given me so much. I played my first game in 2007 as a 20-year-old coming out of university and I've gone through my whole adult life since then, as a single man to meeting my girlfriend, getting married and having our first child. The boys within the club and the club itself have supported me through all of that, which has meant a lot to me."
Glasgow Warriors Assistant Coach Kenny Murray, added: "Pat has been one of the most respected Warriors over the past 11 years.
"He first represented Glasgow at under-16 level and continued to play with the same vigour and enthusiasm that he showed in his early days.
"He has been a key part of our leaders group over recent years and has always been a player that others look up to and hold in huge esteem."