| Harold Breen | |
| Office1: | Secretary of the Department of Supply and Development |
| Term Start1: | 31 July 1949 |
| Term End1: | 16 March 1950 |
| Office2: | Secretary of the Department of Supply |
| Term Start2: | 17 March 1950 |
| Term End2: | 10 May 1951 |
| Office3: | Secretary of the Department of Defence Production |
| Term Start3: | 11 May 1951 |
| Term End3: | 8 August 1957 |
| Birth Name: | Harold Patrick Breen |
| Birth Date: | 30 April 1893 |
| Birth Place: | Richmond, Melbourne |
| Death Place: | Malvern, Melbourne |
| Resting Place: | St Kilda Cemetery |
| Occupation: | Public servant |
| Nationality: |  Australian |
| Spouse: | Agnes Rose O'Sullivan (m. 1916–1923; her death) Rosa Marguerita Maree Carrodus (m. 1930–1934; her death) Constance Jessie Gillespie (m. 1957–1966; his death) |
Harold Patrick Breen (30 April 18936 July 1966) was a senior Australian public servant. He was head of the Department of Defence Production between 1951 and 1957.
Harold Breen was born on 30 April 1893 in Richmond, Melbourne.
He commenced his Commonwealth Public Service career in 1910 in the Department of Defence in the Ordnance Department.
Rising up the ranks, he was appointed Secretary of the Department of Supply and Development in July 1949, and later head of the Department of Supply in 1950.
When the Department of Defence Production was established in 1951, Breen was appointed as its inaugural head. He remained in the position until his retirement in 1957.
Breen died in Malvern on 6 July 1966 and was buried in St Kilda Cemetery.
Breen was appointed a Commander of the Order of the British Empire in June 1953 during his time as head of the Defence Production Department.