A typical 1 cup serving of orange juice contains 1.7 grams of protein (0.7 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.
Only about 6% of the calories in orange juice come from protein, so it is more of an energy food than a protein food. It is worth eating for other reasons; the protein it adds to a day is incidental.
Among the 71 fruits in the database, orange juice 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 248 g. The per-100 g figure lets you compare it directly against any other food here, whatever its serving.
Source: USDA FoodData Central #169098 - "Orange juice, raw (Includes foods for USDA's Food Distribution Program)" (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
Orange juice protein FAQ
How much protein is in orange juice per 100 g?
Orange juice has 0.7 g of protein per 100 g. A typical 1 cup serving (248 g) provides 1.7 g.
Is orange juice a complete protein?
No. Orange juice 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 orange juice cover?
A 1 cup serving of orange juice contains 1.7 g of protein, about 3% of the 50 g reference Daily Value.
Is orange juice a good source of protein?
Orange juice is only a minor source of protein, and about 6% 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).