Four years later he earned acclaim as the first Olympic tennis champion, winning both the singles and doubles titles in Athens. He had developed an interest in the sport as a young boy, and showing a clear aptitude was encouraged by his school teachers to develop his skills. His entry into the competition came about by chance. Boland happened to be visiting his friend Thrasyvoulos Manos in Athens during the Olympics. The latter was a member of the Organising Committee for the Games, and he persuaded Boland to enter the tennis tournament. In the first round of the singles he defeated Germany’s Friedrich Traun, before seeing off two Greeks, Evangelos Rallis and Konstantinos Paspatis to reach the final, where he beat Dionysios Kasdaglis of Egypt to secure the title.
Boland then teamed up with Traun in the doubles, defeating Aristidis and Konstantinos Akratopoulos in the first round before getting a bye in the semi-finals to set up a final against Kasdaglis and Greek player Demetrios Petrokokkinos. When the Union Flag and the German flag were run up the flagpole to honour Boland and Traun's victory, Boland pointed out to the man hoisting the flags that he was Irish, adding "It [the Irish flag]'s a gold harp on a green ground, we hope." The officials eventually agreed to have an Irish flag prepared.
Later on, Boland became active in Irish political and cultural life. In 1908 he became a member of the commission that founded the National University of Ireland, and from 1926 served two decades as the General Secretary of the Catholic Truth Society. He also served as a member of the British parliament between 1900 and 1918, representing the Irish Nationalist Party.
Towards the end of his life he was awarded a papal knighthood, becoming a Knight of St Gregory in recognition for his work in the field of education. He died at his home in London on St. Patrick's Day 1958.