Kahanamoku ya cancanci shiga tawagar 'yan wasan Olympics na Amurka a 1912. A wasannin Olympics na 1912 a Stockholm, ya lashe lambar zinare a cikin
100 mita freestyle, da kuma lambar azurfa tare da na biyu wuri Amurka tawagar a cikin maza 4 × 200 mita freestyle relay.