The 34-year-old, who learned to sail at Restronguet, near Falmouth, sailed into Olympic history at the weekend in winning the Finn class at Weymouth.
Within hours of his triumph, the Royal Mail had selected an image for the stamp which was delivered to more than 500 post offices across the UK, including Truro, by lunchtime.
The post box at the Pandorra Inn, Restronguet, which reopened in March nearly a year after being gutted by fire, was also painted gold.
Hundreds packed Restronguet Sailing Club, where Ben started sailing aged just eight years old, on Sunday to watch the culmination of the competition.
Among them was one of his earliest instructors, 70-year-old Eddie Shelton. He said: "It felt like we were in the boat with him, we were living and dying with him, it's so tough, incredibly mentally draining.
"I had a little tear roll down my face when he won, because we've known him since he was eight, and there's still the same feelings you had when they were young."
He added: "He's just very self-contained, very strong willed and very, very talented, and a lovely lad, a lovely chap. I remember him saying 'I want to go to the Olympics', and it was as simple as that."
