Born Joseph Aloysius Dwan in Toronto, Ontario, Canada, Dwan was the younger son of commercial traveler of woolen clothing Joseph Michael Dwan (1857–1917) and his wife Mary Jane Dwan (née Hunt).
bˈɔːɹn dʒˈoʊsəf ɐlˈɔɪsɪəs dwˈæn ɪn tɚɹˈɑːntoʊ, ɑːntˈæɹɪˌoʊ, kˈænədə, dwˈæn wʌzðə jˈʌŋɡɚ sˈʌn ʌv kəmˈɜːʃəl tɹˈævəlɚɹ ʌv wˈʊlən klˈoʊðɪŋ dʒˈoʊsəf mˈaɪkəl dwˈæn wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd fˈɪfti sˈɛvən nˈaɪntiːnhˈʌndɹɪd sˈɛvəntˌiːn ænd hɪz wˈaɪf mˈɛɹi dʒˈeɪn dwˈæn nˈeɪ hˈʌnt.