Unity Tower (commonly nicknamed the Skeletor (Polish: Szkieletor [ʂkʲɛˈlɛtɔr]) prior to completion) is a 102.5 metre high-rise building located in Kraków, Poland.

The construction of the building was started in 1975, but stopped permanently in 1979 because of economic constraints and political unrest which later culminated in the imposition of martial law in Poland in 1981.

In the 1980s, the building was proposed to house apartments for employees at the Nowa Huta steelworks, and after the fall of communism, a large hotel chain became interested in the facility and wanted to complete the unfinished building, but all these efforts were discouraged by the complicated legal status of the land on which it stood and the high cost of its demolition or adaptation.

German architect Hans Kollhoff was invited to take part in the reconstruction of the building, which was supposed to be completed by the time of UEFA Euro 2012 in Poland and Ukraine.

The long debate about its possible future use based on brand new plans was cut short by the courts in December 2011 because of legal improprieties by its new design team.