Isak Halvorsen was a Norwegian politician for the Liberal Party.

He served as a deputy representative to the Norwegian Parliament during the term 1928–1930, representing the Market towns of Møre og Romsdal county

Market towns of Møre og Romsdal county

The Market towns of Møre og Romsdal county was an electoral district for parliamentary elections in Norway. It comprised the market towns of Kristiansund, Molde and Ålesund in Møre og Romsdal county....

.

Born at Follestad, Skien

Skien

' is a city and municipality in Telemark county, Norway. It is part of the traditional region of Grenland. The administrative centre of the municipality is the city of Skien. Skien is also the administrative centre of Telemark county....

, he got himself a job at the post office in Kristiansund

Kristiansund

Kristiansund is a city and municipality on the western coast of Norway, in the Nordmøre district of Møre og Romsdal county. It was officially awarded township status in 1742, and it is still the major town for the region. The administrative center of the municipality is the city of Kristiansund...

 in 1894. He was a member of Kristiansund city council from 1916 to 1931, and also chaired the local party chapter for some time. Meanwhile, he rose in the postal hierarchy to eventually become postmaster, in the city of Molde

Molde

is a city and municipality in Møre og Romsdal county, Norway. It is part of the Romsdal region. The municipality is located on the Romsdal Peninsula, surrounding the Fannefjord and Moldefjord...

 from 1936 to 1947.

During the German occupation of Norway he was imprisoned for one day, being arrested on 7 October 1944 on suspicion of him having a false passport. He was released the next day.