Topi "Iron Ball" Helin (born November 21, 1978) is a retired Finnish professional Muay Thai kickboxer, four time Finnish Heavyweight Champion and amateur Muay Thai World Champion. In 2003 he turned pro and had his first tournament in K-1 Scandinavia 2005 in Stockholm, Sweden. He trained out of Turku Thaiboxing Club under his mentor and coach WMC World Champion Riku Immonen.
Helin trained Judo as a child around age of 5 or 6, but switched to Wado-ryu Karate at age of 13 and finally to Muay Thai at 15.