If by nominalist you mean someone who does not think that universals exist, that universals are not entities in any way shape or form, not even as 'thoughts' in a divine intellect, then yes Aristotle was a nominalist. That's an established fact, anyone who has read his works knows this.

If by 'nominalist' you mean someone who does not think nature is coherent, and that, in that sense, things can be said to 'have essences' - then no, Aristotle was definitely not a nominalist. He argues against this position in Meta 4 and Meta 10 and in other places.

What really triggers my autism is people who import a Thomist/Avicennist account of individuation into Aristotle when it isn't actually there and is, I would argue, incoherent. And a shitload of other philosophers and scholastics would agree with me. The pseuds who post here think that Aristotle believed in a sort of Fisher Price universe in which an Essence of Man (which is not a universal mind you) becomes 'limited' by 'signate matter' to become Socrates. I think that's retarded. It annoys me that kids like you who have not read Aristotle, or were too dense to follow the arguments, preach this as Aristotelianism. Yes I know about that one line about Socrates and Callias. Aristotle did believe the universe was coherent, that there was such a thing as 'human nature' - and so did Occam. Aristotle did not believe in an Essence as a metaphysical entity. Essences, as universal essences, only exist in your mind, and we acquire them by experience, not by a spooky process of "abstracting essences" with our trusty rusty "agent intellect".

It triggers me even more like pseuds like you claim that a "nominalist" reading of Aristotle is what caused the modern world and explains your inceldom. The actual contours of this debate are likely too subtle for the likes of you. Fuck off and go read the Metaphysics five times in a row.