Mike Perham, 14, waved his fist triumphantly to a small crowd of Antiguan officials and supporters as he docked his 28-foot sailboat outside St. John's on the southeastern side of the island.
Perham, who was followed by his father during his journey, set sail Nov. 18 from Gibraltar and made brief stops for repairs in the Canary Islands and Cape Verde.
Perham, of Potters Bar, Hertfordshire, was seeking to break the record held by Sebastian Clover, also of Britain, who was 15 when he sailed solo from the Canary Islands to Antigua in 2003.
Perham had been expected to reach Antigua on Tuesday but a late problem with a sail delayed his arrival.
Antigua radio hosts Jolyon and Judy Byerley have been following Perham's trip for nearly a month and have been broadcasting news of his progress from their home-based studio.
Perham broke the record held by another British yachtsman, Sebastian Clover, who sailed from the Canary Islands to Antigua in January 2003 at the age of 15.
Sailor Fred Vonik was also full of praise. "I think it is a very impressive achievement," he said. "At 14, most people might do a bit of dinghy sailing or windsurfing. And to cross the Atlantic, it's a huge achievement."
"It's a journey that most sailors never even achieve in their entire life, so to do it at the age of 14 is very impressive," Vonik said.