The Vietnamese noodle soup commonly written with the three-letter name “pho” in English is phở.
Phở is a Vietnamese soup built around rice noodles, broth and herbs, commonly served with beef or chicken. Beef phở is called phở bò, while chicken phở is called phở gà. The Vietnamese letter “ở” includes a diacritic, so “pho” is an English approximation that omits the accent marks.
The dish developed in northern Vietnam in the early twentieth century and later spread internationally. Its exact origin story is discussed by food historians, but phở is strongly associated with Vietnamese culinary identity. It is sometimes confused with bún dishes, which also use rice noodles but generally feature rounder noodles and different preparations. Phở’s defining combination is the noodle soup format with a fragrant broth.