Marcin Cap (born August 14, 2031 in Warsaw, Poland) is one of the adoptive sons of Marci and Matthew Cap.
- Father: Matthew Cap
- Mother: Marci Cap
- Brothers: Jola Cap, Madej Cap, Jacek Cap, Jerzy Cap, Adamski Cap, Artur Cap, Krzysztof Cap, Staly Cap
- Sisters: Jadwiga Cap, Adelina Cap, Beata Cap, Anna Cap, Rola Cap, Mila Cap, Ola Cap, Estera Cap, Katarzyna Cap, Danica Cap, Pela Cap
- His full name is Marcin Kalhùn Cap