| Klaus Lanzarini | |
| Fullname: | Klaus Lanzarini |
| Nationality: | Italian |
| Club: | Gruppo Sportivo Fiamme Gialle BPAM Montebelluna |
| Birth Date: | 18 January 1977 |
| Birth Place: | Latina |
Klaus Lanzarini (born 18 January 1977 in Latina) is a former international freestyle swimmer from Italy, who participated at the 2000 Summer Olympics for his native country. He is best known for winning the gold medal in the men's 4 × 100 m freestyle at the 2006 FINA Short Course World Championships in Shanghai, PR China.