Sergio Liani (born 3 August 1943) is a retired Italian hurdler. He competed at the 1968 and 1972 Olympics in the 110 m event, but failed to reach the final.
During his career Liani won four national 110 m titles, in 1970, 1971, 1973 and 1977. He set his personal best (13.6 seconds) in June 1971 in Prague.
He won 7 national championships at individual senior level.