The 33-year-old announced his decision on Twitter, saying that it had been due mainly to life in the paid ranks having become a “burden financially”.
Macaulay, who joined forces with Wallace Booth and Gavin Dear to see Scotland crowned as world amateur champions in 2009, also revealed his enjoyment for the game had waned in recent years.
“I have been considering my golf career for a number of months now, and after a lot of thought I have decided to call it a day on my professional career,” wrote the Tulliallan man in a post on Twitter.
“I have enjoyed a good chunk of my professional life, but for the last couple of years it has become a burden financially and also on my family.
“I have other people in my life now who are more important to me than golf.
“I would like to thank the people who have supported me until the very end (you know who you are) but most of all my family, my mum and dad, and (wife) Clare-Marie.”
Macaulay, who won the Scottish Amateur Championship at Carnoustie in 2008, secured his European Tour card the following year after coming through all three stages of the Qualifying School.
In only his fifth event on the circuit, he finished second, a shot behind Argentina’s Tano Goya, in the Madeira Island Open.
The Scot equalled the course record with a brilliant 64 in the final round, making birdies at eight of the last nine holes as he stormed home in 28 - one outside the Tour record.
However, he struggled to back up that eye-catching performance and, in 2014, started driving a taxi in an attempt to make ends meet.
Macaulay had been playing a bit more recently, teeing it up on the third-tier PGA EuroPro Tour over the past two weeks at Ballykisteen and Frilford Heath.
But, like Dear did after a short spell in the paid ranks, he has now decided that enough is enough.
“I plan to apply for my amateur status back,” added Macaulay. “I may even begin to enjoy playing it again in due course.
“However, I have been presented with a great opportunity to pursue a new career away from professional golf, and I’m relishing the new challenge.”