[4] Gunnar Knudsen started studying at Chalmers University of Technology in Gothenburg, Sweden in 1865 where he got a degree as engineer in 1867.

[5] Returning to Norway, he started working at Aker's Mechanical Workshop and then went to England where he studied ship building technics at Piles Shipyard in Sunderland.

In social policy, Knudsen's time as prime minister saw the passage of the Sickness insurance Law of September 1909, which provided compulsory coverage for employees and workers below a certain income limit, representing approximately 45% of all wage earners.

In 1915, free midwife services were extended to the wives of men included under the national health insurance scheme.

[10][11] Gunnar Knudsen married Anna Sofie Cappelen (1854–1915) in 1880, and together they had five children, born between 1882 and 1893; Erik, Christen, Gudrun, Margit and Rolf.