Provision of a pneumatic tire with further enhanced low noise performance during running. Plural land portion rows are formed in a tread section (16) by forming circumferential direction main groove(s) extending along the tire circumferential direction. A fine-grooved-and-siped rib (34) configuring one of the land portion rows is configured with a fine groove (36) extending along the tire circumferential direction, a projecting sipe (38) projecting out from the fine groove (36) towards the side of a tire equatorial plane (CL) and open to a circumferential direction main groove (22E); and a plain rib portion (40) adjacent to the fine groove (36) on the vehicle mounting outside (SE), the plain rib portion (40) configured with a circular shaped peripheral face across the entire face on a ground contact side.