Roman Vajs (born 18 November 1974 in Liptovský Mikuláš) is a Slovak slalom canoeist who competed at the international level from 1990 to 2004. Vajs won two medals in the C2 team event at the ICF Canoe Slalom World Championships with a silver in 1999 and a bronze in 1993. He won the overall World Cup title in the C2 class in 1998. He also won 3 medals at the European Championships (1 gold, 1 silver and 1 bronze). Vajs finished 13th in the C2 event at the 1996 Summer Olympics in Atlanta.