[3] As a young man, Begg played rugby union for the North East Valley and Union clubs, was captain and president of the Dunedin Cycling Club, and was a lieutenant in the North Dunedin Rifles.

However, in November 1903, his father was killed in a boating accident at Pūrākaunui, and Begg was obliged to return to Dunedin to take over the running of the family company.

[3] Begg entered public life in 1909, when he was elected as a member of the North East Valley Borough Council.

[5][7] Begg served a two-year term as mayor of Dunedin from 1919 to 1921, during which time he hosted the visit to the city of the Prince of Wales in 1920.

[8] Begg served as a member of the Otago Harbour Board from 1929 until 1947, including three years at chairman.