The simple wooden seat is on the north coast cliff path, half-way between Plémont and Grosnez – an area that he loved.
The bench carries the inscription ‘Never let a person sit alone’, with a plaque showing the location of a star that has been named after him.
Funding for the bench was raised by friends at a celebration of his birthday earlier this year. The blessing was conducted by the Rector of St Ouen, the Rev Ian Pallent.
Mr Miller (24), a former Victoria College student, was found murdered on a beach on the island of Koh Tao, in Thailand, just over a year ago.
The trial of two Burmese men accused of his murder and that of Hannah Witheridge (23) from Norfolk is ongoing.