Gordon, 30, a double British Lion, who made the first of his 75 Scotland appearances eight years ago, said: "This has been a difficult decision as I have always regarded selection for my country as a huge honour and not something that I would ever take for granted.
"I have discussed matters with my wife and family and believe the time is now right to bring my Scotland career to an end. I want to thank all those who have supported me over the years.
"The physical commitment to play international rugby is widely recognised but there is also a huge time commitment and you cannot compromise when it comes to international rugby. It has to be everything.
"During my career I have not had many injuries and, in one guise or another, I have spent every summer away playing rugby since 1994, often in the intense environment of the Test arena.
"I have joined Leeds Tykes on a two year contract and I am looking forward to playing club rugby. International rugby is now a closed chapter for me.
"I have been immensely proud to pull on the Scotland jersey and to lead my country in 11 internationals. I enjoyed the recent Lions tour to New Zealand and was privileged to captain the team to victories against Otago, Manawatu and Auckland.
"My decision is not about coaching regimes, leaving the Glasgow Warriors or joining Leeds. It's about what's best for me at this stage of my rugby career and in my personal life."
SRU acting director of rugby, Richie Dixon, who as Scotland coach awarded Bulloch his first cap against South Africa in 1997 and also coached him at pro-team level with Glasgow, said: "Gordon has been an outstanding ambassador for Scottish Rugby and while we always want to have as wide a pool of quality players from which to select the Scotland team, we respect his decision.
Throughout his career he has worked diligently to get better and has been an exemplary professional. I will remain in contact with him to endeavour to ensure his experience can be used to best advantage for Scottish Rugby."
Jon Petrie, who has succeeded Bulloch as both Glasgow Warriors and Scotland captain, said: "Gordy is a great mate of mine - someone from whom I have learned a lot as a friend, player and captain. In that respect I'm sad to see him go but can understand his decision.
"Competition at hooker is certainly hotting up with a number of quality players in contention."