Major General Bo Gerhard Otto Varenius (3 November 1918 – 23 July 1996) was a senior Swedish Coastal Artillery officer.

[4] He felt at home in the archipelago environment and saw it as a challenge to work with the problems with coastal defence.

[4] During his first years as an officer, he served in troop and staff positions in Karlskrona Coastal Artillery Regiment.

[6] He then served from 1966 to 1970[4] as head of Section 1 in the Defence Staff, with responsibility for the Quartermaster Department and signal service.

[4] During his twelve years as Chief of the Naval Staff, Varenius participated in the major changes in the naval war organization during the transition from the destroyer era to the missile age, as well as from older coastal artillery batteries and mine units to fixed and mobile coastal artillery units.