HDMS Najaden

Several ships of the Royal Danish-Norwegian Navy (1509–1814) and the Royal Danish Navy have borne the name Najaden after the mythological water spirit, including:
 * HDMS Najaden (1796), a frigate (1796–1807)
 * HDMS Najaden (1811), a frigate (1811–1812)
 * HDMS Najaden (1820), a corvette (1820–1852)
 * HDMS Najaden (1854), a corvette (1854–1865)
 * HDMS Najaden (1913), a submarine (1913–1931)
 * HDMS Willemoes (1947), a torpedo boat (1947–1966), originally named Najaden
 * HDMS Najaden (1963), a patrol vessel (Danish: bevogtningsfartøj) (1963–1991)