Neil Cusack (born 30 December 1951 in Limerick) is a retired middle and long distance runner from Ireland.
Cusack was born in Limerick city in 1951 and attended St Munchin's secondary school. Cusack attended East Tennessee State University. In 1972 he was the NCAA Men's Cross Country National Champion.
Cusack won the Boston Marathon in 1974. He remains the only Irish athlete to have won in Boston. In 1981 Cusack won the Dublin Marathon.
Cusack represented Ireland in the 1972 Summer Olympics in Munich, Germany and in the 1976 Olympic Games in Montreal, Canada.