Hamza débute le football à Bron et porte les couleurs des clubs du SC Bron-Terraillon (2005-2009) et de l'AS Bron Grand-Lyon (2009-2010). La saison suivante, il intègre les effectifs de l'Olympique Lyonnais. Ce milieu de terrain est international U17.
Olympique Lyonnais and Juventus have reached an agreement for the transfer of Hamza Rafia to the Italian club, which has paid €400,000 for the 20-year-old midfielder. The deal also included incentives that can reach €5M, as well as 20% on the added value of a possible future transfer.