| Gunnar Hellesen | |
| Office: | County Governor of Rogaland |
| Term Start: | 1968 |
| Term End: | 1973 |
| Primeminister: | Per Borten Trygve Bratteli Lars Korvald |
| Predecessor: | Paul Ingebretsen |
| Office2: | Minister of Defence |
| Term Start2: | 5 June 1970 |
| Term End2: | 17 March 1971 |
| Primeminister2: | Per Borten |
| Predecessor2: | Otto G. Tidemand |
| Successor2: | Alv Jakob Fostervoll |
| Office3: | Member of the Norwegian Parliament |
| Term Start3: | 1 October 1961 |
| Term End3: | 30 September 1969 |
| Constituency3: | Rogaland |
| Birth Date: | 23 February 1913 |
| Birth Place: | Haugesund, Rogaland, Norway |
| Death Place: | Haugesund, Rogaland, Norway |
| Party: | Conservative |
Gunnar Fredrik Hellesen (23 February 1913 - 7 July 2005) was a Norwegian politician for the Conservative Party.
He was born in Haugesund.
He was elected to the Norwegian Parliament from Rogaland in 1961, and was re-elected on one occasion. He had previously served in the position of deputy representative during the term 1958 - 1961.
On 5 June 1970, he was appointed Minister of Defence during the centre-right cabinet Borten, replacing Otto Grieg Tidemand who on the same day became Minister of Trade and Shipping. Hellesen held the position until the cabinet Borten fell in 1971.
Hellesen was a member of Haugesund city council from 1945 to 1963, serving as mayor in from 1955 to 1959. He served as County Governor of Rogaland from 1968 to 1973.