They are Pham Duc Anh, Dinh Quang Hieu and Bang Thanh Lam from Hanoi, and Hoang Nghia Tuyen from the province of Nghe An.
They will compete against 77 of their peers from countries around the globe.
At the competition last year in Tbilisi, Gruzia, Vietnamese youth won two gold medals.
The International Chemistry Olympiad is an annual academic competition for high school students. It was first held in Prague in 1968 and has been held annually since then, with the exception of 1971.