The eight-year-old, who won over £2m in prize-money, also won the Long Distance Cup on Champions Day twice and an Ebor.
Trained by John and Thady Gosden, he returned from an eight-month lay off to run a tremendous race in this year's Gold Cup, pushing his much younger rival Scandinavia all the way before succumbing by just a head.
He took on that same rival again but in an unsatisfactory race where he was hampered by a loose horse, he was beaten a long way.
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Just this year the Gosdens realised he had a condition in his eyes that made them very sensitive to sunlight and he has been wearing ski goggles to protect them from the sun.
"Trawlerman is happy and well, but unfortunately he came out of the Goodwood Cup with a leg issue and is now being retired," John Gosden told www.godolphin.com.
"At eight years old, he has become part of the family here and won the Long Distance Cup twice and the Ascot Gold Cup in a very fast record time, which is unlikely to be equalled, as well as the Ebor.
"He has won over £2m in prize-money and remained at the top of his game this year when second in the Ascot Gold Cup, beaten a head giving 1lb to the winner.
"He will be retired to Wood Ditton Stud, where Godolphin have wonderful facilities that he knows well having been there for holiday.
"For all of us at Clarehaven Stables, just like Stradivarius, Trawlerman has become a much-loved member of the family and there are a lot of people here who will miss him particularly Ben de Paiva, who looks after him and Richard Wilkinson, who rode him through most of his career."
