The side had a convincing 62-run win in the final against Hamilton Boys' High School in the final yesterday afternoon to repeat its win of last year.
The tournament's first two days were washed out on Monday and Tuesday so the format was converted to twenty/20 matches for the last two days.
Otago Boys' won its two games on Wednesday and continued on its winning way yesterday morning against Hutt International Boys School.
Hutt scored 58 when it batted first, with Kane Johnston, Jack Pryde and Taine Bayly picking up two wickets each. Otago Boys' was four wickets down when it reached the small target in the 17th over.
In the final, Otago Boys' batted first and made 136 for seven wickets. Bayly led the way with a fine unbeaten 74, hitting 38 of those runs in boundaries. Cameron McAuslen chipped in with 24.
In reply, Hamilton Boys' was 74 for eight wickets at the end of its overs. Pryde took three cheap wickets while Johnston bagged a couple.
The side was made up of year 10 pupils with two year 9 pupils also chiming in.