Herbert Ditty was elected to Belfast City Council in 1973, representing the Ulster Unionist Party. He was appointed as High Sheriff of Belfast in 1985. Ditty was Deputy Lord Mayor in 1991 and served as Lord Mayor the following year.

Ditty lived in the Shankill Road area of Belfast. He served as chairman of the North Belfast Unionist Association and was active in the Unionist Labour Movement.

Ditty was a member of the Ulster Protestant Action Executive, when the group was founded at a special meeting at the Ulster Unionist Party offices in Glengall Street, Belfast.