Szilárd or Szilard is a Hungarian given name or surname. It is a Hungarian version (literary translation) of the name Constantine. It may refer to:
People First name Szilárd Bogdánffy (1911–1953), Hungarian Roman Catholic bishop Szilárd Borbély (1963–2014), Hungarian writer Szilárd Devecseri (born 1990), Hungarian football player Szilárd Éles (born 1987), Hungarian football player Szilárd Keresztes (born 1932), Hungarian Greek Catholic bishop Szilárd Németh (footballer) (born 1977), Slovak football player Szilárd Németh (politician) (born 1964), Hungarian politician Szilárd Tóth (born 1973), Hungarian ice dancer
Surname Leo Szilard (1898–1964), Hungarian physicist
Other uses 38442 Szilárd, main belt asteroid discovered in 1999 Einstein–Szilard letter, sent to Franklin Roosevelt in 1939 Einstein–Szilárd refrigerator or Einstein refrigerator, a type of absorption refrigerator with no moving parts Szilard (crater) Szilárd petition