| Office: | Minister of Labour |
| Term Start: | 6 March 1923 |
| Term End: | 25 July 1924 |
| Primeminister: | Otto B. Halvorsen Abraham Berge |
| Predecessor: | Ole M. Mjelde |
| Successor: | Ole M. Mjelde |
| Term Start2: | 21 June 1920 |
| Term End2: | 22 June 1921 |
| Primeminister2: | Otto B. Halvorsen |
| Predecessor2: | Ole M. Mjelde |
| Successor2: | Ole M. Mjelde |
| Office3: | Member of the Norwegian Parliament |
| Term Start3: | 1 January 1922 |
| Term End3: | 31 December 1924 |
| Constituency3: | Market towns of Vest-Agder and Rogaland counties |
| Term Start4: | 1 January 1919 |
| Term End4: | 31 December 1921 |
| Constituency4: | Holmen, Stavanger |
| Birth Date: | 12 April 1869 |
| Birth Place: | Stavanger, Rogaland, Sweden-Norway |
| Death Place: | Stavanger, Rogaland, Norway |
| Party: | Conservative |
Cornelius Middelthon (12 April 1869 – 6 April 1934) was a Norwegian grocer and politician of the Conservative Party who served as Minister of Labour from 1920 to 1921 and again from 1923 to 1924.