HDMS Slesvig (Sleswig) was a ship of the line of the Royal Danish Navy, which she served from 1725.

Slesvig was built at Nyholm to a design by Ole Judichær She was laid down in 1723 and launched on 25 April 1725.

[2] In 1726 Slesvig was one of the ships of the line in the Danish squadron that, together with the British, blockaded Reval (modern-day Tallinn).

On the return voyage to Copenhagen, she and two other ships became separated from the main squadron in a westerly gale south of Gulland (Gotland).

The trials resulted in the shortening of her masts, more ballast and lighter guns – all of which improved Slesvig's performance somewhat, although she was still not a good sailing ship.

Martinus Mundelaer, another Dutchman from Ostende, served as Chief Quarter Master (overkvartersmester).

The ship journal was kept by mate Johan Otto Rotwitt-[6] Slesvig sailed from Copenhagen on 17 February 1741.