The 25-year-old signs from the Ugandan league joining international team-mate Kisekka at Dong Nai FC
Wasswa, a defending midfielder, has featured 33 times for the African nation and had previousl spent time in the Turkish second-tier with Karabukspor, Altay and Keyseri Erciyesspor.
The 25-year-old will play as a centreback for his new club, replacing Dutch defender Danny van Bakel who has departer for Thanh Hoa FC.
Wasswa had made his way to Vietnam following recommendation from his Uganda team-mate Henry Kisekka who plays for Dong Nai as well.
Dong Nai coach Tran Binh Su told Goal Vietnam exclusively : "Dong Nai has signed two-year contract with Hassan Wasswa. He is a strong and versatile player who is suitable to our playing style."