Bus line 109 will offer a direct connection from downtown HCM City to Terminal 3 at Tan Son Nhat International Airport with the detailed route as follows:

Terminal 3 at Tan Son Nhat International Airport (Photo by Trinh Nguyen)
From Saigon Bus Station to Terminal 3: Saigon Bus Station-Pham Ngu Lao Street – Yersin Street-Tran Hung Dao Street-Ham Nghi Street-Pasteur Street-Vo Thi Sau Street-Nam Ky Khoi Nghia Street-Nguyen Van Troi Street-Phan Dinh Giot Street-Phan Thuc Duyen Street-18E Street-Tan Son Nhat International Airport Terminal 3.
From Terminal 3 to Saigon Bus Station: Tan Son Nhat International Airport Terminal 3-C2 Street-Hoang Hoa Tham Street-Cong Hoa Street-Hoang Van Thu Street-Nguyen Van Troi Street-Nam Ky Khoi Nghia Street-Ham Nghi Street-Le Lai Street-Saigon Bus Station.
The fare for this route is VND5,000-6,000 per trip. The buses have free Wi-Fi, smart electronic displays, and various payment options.
At present, bus routes to Tan Son Nhat International Airport include Route 152 (Trung Son Residential Area-Ben Thanh-Tan Son Nhat International Airport), Route 72-1 (Tan Son Nhat International Airport-Expressway-Vung Tau Bus Station), Route 109 (Saigon Bus Station-Tan Son Nhat International Airport), and Route 103 (Cho Lon Bus Station-Nga Tu Ga Bus Station).