A typical 1 cup serving of coconut water contains 1.7 grams of protein (0.72 g per 100 g), which makes it only a minor source of protein. That covers roughly 3% of the 50 g reference Daily Value, so it adds toward your protein total for the day.
Around 15% of the calories in coconut water come from protein, so it is more of an energy food than a protein food. It contributes to a day's protein total, but the bulk of what it delivers is energy rather than amino acids - treat it as a contributor alongside a denser source, not as the protein in a meal.
Among the 71 fruits in the database, coconut water ranks 13th by protein per serving, and 673rd out of all 796 foods on the site. Set against currants, another fruit entry in the database, a serving carries about 0.5 g more protein (currants has 1.2 g per 1/4 cup).
It is an incomplete protein on its own; pairing it with other plant foods across the day covers the full range of essential amino acids. The serving above is measured by volume at 240 g. The per-100 g figure lets you compare it directly against any other food here, whatever its serving.
Source: USDA FoodData Central #170174 - "Nuts, coconut water (liquid from coconuts)" (SR Legacy, published 4/1/2019). Values are the published reference figures for that record, not lab measurements for a specific brand or batch.
Quick answers
Coconut water protein FAQ
How much protein is in coconut water per 100 g?
Coconut water has 0.72 g of protein per 100 g. A typical 1 cup serving (240 g) provides 1.7 g.
Is coconut water a complete protein?
No. Coconut water is an incomplete protein on its own; pairing it with other protein sources across the day covers the full range of essential amino acids.
How much of the Daily Value does a serving of coconut water cover?
A 1 cup serving of coconut water contains 1.7 g of protein, about 3% of the 50 g reference Daily Value.
Is coconut water a good source of protein?
Coconut water is only a minor source of protein, and about 15% of its calories come from protein, which makes it more of an energy food than a protein food. Set against currants, another fruit entry in the database, a serving carries about 0.5 g more protein (currants has 1.2 g per 1/4 cup).