Ba River (Vietnamese: Sông Ba, also known as Ea Pa, Ia Pa, Krông Pa or Đà Rằng River) is a river in the South Central Coast region of Vietnam.

It has its source in Kon Tum Province and flows into the South China Sea in Tuy Hòa, Phú Yên Province.

[1] The river's water volume varies significantly throughout the year, with only 47 and 45 m3/s in March and April and 366, 682, and 935 m3/s in September, October, and November.

They include a Sanskrit inscription from the fifth century at its mouth and various Champa sites, including the citadel Thanh Ho around 15 km inland.

[2] The river certainly provided an important route far into the interior for the Cham people,[2] who were involved in trade with both their highland hinterlands and seagoing merchants.