If their website is to be believed, yes:

"Solein is 65-70 % protein, 5-8 % fat (primarily unsaturated fats), 10-15 % dietary fibres and 3-5 % mineral nutrients. The macronutrient composition of the cells is very similar to that of dried soy or algae. Solein provides iron, fibre and B vitamins.

While protein is found in both plant and animal-based foods, edible proteins are not all the same. They are made up of different combinations of amino acids and are characterised by the ratio and amount of essential amino acids they have.

Solein contains all of the nine essential amino acids that are required by the human body."

https://solarfoods.com/solein/

The FDA wouldn't let them label it with any protein if it wasn't complete. We already have a laundry list of CO2 consuming creatures that are complete protein sources. And theirs is new and proprietary. So it's gotta be. https://en.wikipedia.org/wiki/Single-cell_protein#Microorgan...

Really? In Australia Oats are labelled as having protein in the nutritional information but they are deficient in lysene.

Protein is listed in the nutrition facts all over the world. What GP is saying is that for Solein to be advertised and labeled as a protein it has to be a complete protein. This seems fairly accurate believable, but I know there are protein powders that are not complete proteins (typically not sold in grocery stores though)

If it has a similar profile to soy or algae like they claim it is a complete protein, or else that’s a false statement.

Australia (and Solar Foods for that matter) are not beholden to the American FDA.