Yes. In fact both countries had combat troops helping South Vietnam during the Vietnam war.
The answer is yes, South Korea was in the Vietnam War!
US allies were South Korea, Australia, New Zealand, Thailand, Philippines, and the Republic of South Vietnam.
Australia, New Zealand, Thailand, South Korea, Philippines (Plus the US & Republic of South VN).
US, Australia, New Zealand, Philippines, South Korea, South Vietnam, Thailand verses NORTH VIETNAM (supplied by Communist China/USSR) & their southern guerrilla allies (the Viet Cong).
Fought with the allies in South Vietnam.
Australian troops were fighting in Vietnam as allies of South Vietnam, along with those of the US, South Korea, and New Zealand. Militarily, each of the allies fulfilled different roles and employed different approaches and tactics. See the Web Link to the left for further information.
The Soviet Union and China were two significant allies of North Vietnam during the Vietnam War. The war lasted from 1955 to 1975.
Those statistics are itemized on the "Vietnam War casualties" website.
The communist North Vietnam or PAVN and their allies vs. the Republic South Vietnam with America and their allies
New Zealand, US, South Korea, South Vietnam, Philippines, Thailand.
North Vietnam=Air War South Vietnam=Ground & Riverine War