Katsuki is a young man of above-average height, with a slim, muscular build, and a fair skin tone. He has short, spiky, sandy blond hair with choppy bangs that hang over his eyebrows. His eyes are sharp and bright red in color.

During his time in Aldera Junior High School, similar to Izuku, he wore a plain black gakuran uniform with yellow buttons, accompanied by brown loafers. While at home, he wears a green jinbei over a white shirt and gray sweatpants.

At U.A., he wears the standard U.A. un