Romolo Alzani (born 6 March 1921 in Rome; died 3 October 2002) was a professional Italian football player. He was the part of the very reliable defensive formation of S.S. Lazio for several years that was called "iron defense" ("la difesa di ferro"). Overall, he played for 10 seasons in the Serie A for A.S. Roma and Lazio, collecting 247 appearances and 6 goals.