The Nghinh Ong Thang Tam Festival in Vung Tau is among the signature folk celebrations of Southern coastal communities, especially fishermen in Ba Ria–Vung Tau Province. Held at the Lang Ong Nam Hai – Thang Tam complex, the festival venerates Cá Ông (the whale), revered by fishermen as a sacred deity who shields them for safe voyages. It is a time for fishing communities to express devotion, give thanks to the sea, and pray for fair winds and favorable catches. The festival consists of two parts: the solemn rites—with the procession bringing the whale’s spirit tablet from the sea to the shrine, sacrificial offerings, and incense prayers—and the lively festivities with folk culture activities such as hát bội (classical opera), boat races, folk games, martial arts performances, and lion–unicorn–dragon dances. Together they create a vibrant atmosphere rich in tradition. Beyond its profound spiritual meaning, the festival strengthens community bonds and draws large numbers of residents and visitors to Vung Tau. With its unique cultural value, the Nghinh Ong Thang Tam Festival has been recognized as a National Intangible Cultural Heritage of Vietnam, underscoring the depth of the country’s maritime culture.