Namesakes
John A. Costello
(m) 1891-1976 
Irish Presidents and Prime Ministers 1948-1951; 1954-1957 (prime minister)
Dolores Costello
(f) 1903-1979
Notable Actors and Entertainers (actor)
Lou Costello
(m) 1906-1959
Notable Actors and Entertainers (comedian)
Larry Costello
(f) 1931-2001
Hall-of-Famers 2022 (basketball)
Elvis Costello
(m) 1954-
Notable Musicians
Rock and Roll Hall-of-Famers 2003 Elvis Costello & the Attractions
Declan Costello
(m)
Fictional Characters from Television 1994 Heartbreak High