A titanium oxide powder of the present invention has a BET specific surface area of 5 m2/g or more and 15 m2/g or less and contains polyhedral-shaped titanium oxide particles having eight or more faces, in which a mass reduction rate in a case of being heated at 800° C. for 1 hour in an air atmosphere is 0.03% by mass or more and 0.5% by mass or less.