Four or more cups of coffee a day can reduce the combined risk of both diseases by 39 per cent, it is claimed.
Scientists pooled information from nine studies of head and neck cancers, comparing regular coffee drinkers and people who avoided coffee.
They found a strong association between frequent coffee drinking and lower rates of oral cavity and pharynx (mouth and throat) cancers.
Tea drinking had no effect on head and neck cancer risk.
The lead researcher, Dr Mia Hashibe, from the University of Utah, in the United States, said: "Since coffee is so widely used and there is a relatively high incidence and low survival rate of these forms of cancers, our results have important public health implications that need to be further addressed.
"What makes our results so unique is that we had a very large sample size."