People in Hanoi can see 71 percent of the eclipse and those in Ho Chi Minh City, 36 percent.
The eclipse will begin in Vietnam at 1:16 p.m. and reach its peak at around 2:55 p.m. before ending at 4:18 p.m.
This will be one of two solar eclipses in 2020. The second, a total eclipse on December 14, will be visible from South America.
A solar eclipse occurs when the disk of the moon appears to cross in front of the disk of the sun.
An annular eclipse occurs when the sun appears as a bright ring, or annulus, surrounding the dark disk of the moon.
The last solar eclipse seen in Vietnam was an annular eclipse on December 26 last year.
Scientists have sounded the usual warning: sky watchers should only see the eclipse indirectly or with proper glasses to prevent retinal burns.