His Majesty, King Carl XVI Gustaf is the Patron and First Honorary Fellow of the Royal Society of Naval Sciences.

New fellows are elected each year at the ordinary session that precedes the Annual General Meeting on November 15th. Fellowship is open to all Swedish nationals who can be expected to play an active part in the promotion of the objectives of the Society. There are three categories of fellowship: honorary fellows, ordinary fellows and corresponding fellows. Any foreign national who fulfils the aforementioned conditions is eligible for election to honorary or corresponding fellowship. The number of ordinary fellows under the age of 60, is not to exceed 120.

Presently (2023), the Society includes c.a 350 fellows.