Provided is a boron nitride powder including: an agglomerated particle obtained by aggregating flaky primary particles, in which in-plane directions of the primary particles are oriented in a direction parallel to a short-side direction of the agglomerated particle. In addition, provided is a method for producing a boron nitride powder including: a nitriding step of firing a boron carbide powder having an aspect ratio of 1.5 to 10 in a nitrogen pressurized atmosphere to obtain a fired product; and a crystallization step of heating a formulation that contains the fired product and a boron source to produce flaky boron nitride primary particles and obtaining a boron nitride powder containing an agglomerated particle obtained by aggregating the primary particles.