Coles was managing director of G. J. Coles & Co from 1923 to 1931, when, after some illness he handed the leadership role to Arthur, but remained as chairman of the board (despite very public opposition to his autocratic style) until 1956. He maintained membership on the board until 1976, when he retired. With his role in the company reduced, he was able to devote his time and energies to philanthropic and political causes. He was on the board of the
Alfred Hospital and from 1933 its honorary treasurer. He was an active member of St John's Anglican Church in
Toorak. He was an active member of
Rotary and president of its Melbourne club in 1934. He helped found the
Institute of Public Affairs, and was its president in 1965. He expounded on his philosophies in an interview in the January 1966 issue of their newsletter . With fellow businessmen
R. M. Williams and
Sam Hordern he helped found the
Equestrian Federation of Australia in 1951 to support Australia's
1956 Olympic Games equestrian team. Because of
quarantine restrictions, these events were held in
Stockholm, Sweden rather than the Olympic host city,
Melbourne. He was on the board of the Victorian Hospitals and Charities Commission from 1935. He was on the board of the National Bank. He was an active member of the
Royal Melbourne Golf Club and the Peninsula Golf Club (including a four-year term as president), the
Athenaeum Club, the
Victoria Racing Club and the
Melbourne Cricket Club. ==Awards==