Costanzo was born in Rome, the son of journalist and TV presenter Maurizio Costanzo and writer Flaminia Morandi, and the brother of writer/director Camilla Costanzo.
kɔstˈænzoʊ wʌz bˈɔːɹn ɪn ɹˈoʊm, ðə sˈʌn ʌv dʒˈɜːnəlˌɪst ænd tˌiːvˈiː pɹɪzˈɛntɚ mɔːɹˈɪzɪˌoʊ kɔstˈænzoʊ ænd ɹˈaɪɾɚ flæmˈɪniə mɔːɹˈændi, ænd ðə bɹˈʌðɚɹ ʌv ɹˈaɪɾɚ slˈæʃ dᵻɹˈɛktɚ kæmˈɪlə kɔstˈænzoʊ.