The Four Immortals (Vietnamese: Tứ bất tử, chữ Hán: 四不死) refers to the four chief figures in the pantheon of genii worshiped by the Vietnamese people of the Red River Delta region in legend and mythology.

[1] They are Tản Viên Sơn Thánh (chữ Hán: 傘圓山聖), also known as Sơn Tinh (山精) the god of Tản Viên Mountain, Phù Đổng Thiên Vương (扶董天王, also known as Thánh Gióng, Ông Dóng) a giant who defeated northern invaders, Chử Đồng Tử (褚童子) a sage, and Princess Liễu Hạnh (柳杏公主), a heavenly spirit and Mother Goddess.

Full development of the mythology and honouring of the Four Immortals took place in the Lê dynasty.

[2] Each of the four immortals has association with helping historical national figures.

For example, Thánh Gióng in legend helped the sixth Hùng King to repulse foreign invaders.