A planar light source includes a support member; a light guide member including a first surface located proximate to an upper surface of the support member, a second surface opposite to the first surface, and a through hole extending from the first surface to the second surface; a light source unit including a light-emitting element and a wavelength conversion member that covers an upper surface and a lateral surface of the light-emitting element and disposed on the support member at a position of the through hole; a light-transmissive member disposed between the light source unit and the light guide member in the through hole; and a light adjustment member disposed on the light source unit and the light-transmissive member. An upper surface of the wavelength conversion member of the light source unit is located higher than the second surface of the light guide member.