German submarine U-546 was a Type IXC/40 U-boat operated by Nazi Germany's Kriegsmarine during World War II. She was laid down at the Deutsche Werft in Hamburg as yard number 367 on 6 August 1942, launched on 17 March 1943 and commissioned on 2 June 1943 under Oberleutnant zur See Paul Just. The U-boat was a member of three wolfpacks.

The Type IX U-boat was designed by Nazi Germany's Kriegsmarine in 1935 and 1936 as a large ocean-going submarine for sustained operations far from the home support facilities. Type IX boats were briefly used for patrols off the eastern United States in an attempt to disrupt the stream of troops and supplies bound for Europe. It was derived from the Type IA, and appeared in various sub-types.