A pneumatic tire provided with a sipe in a tread portion, the pneumatic tire comprising, in the tread portion: a first sipe wall surface of a pair of sipe wall surfaces (80a, 80b) that face a space of the sipe, the first sipe wall surface comprising a first wave-like portion at each position in an extension direction of the sipe in which the sipe extends on a tread surface, the first wave-like portion being bent in a wave-like shape to form a surface recess and protrusion along a sipe depth direction and comprising at least two first peak portions (80M1, 80M2) and at least one first valley portion (80V1), and a second sipe wall surface of the pair of sipe wall surfaces (80a, 80b) comprising a second wave-like portion at each position in the extension direction of the sipe, the second wave-like portion being bent in a wave-like shape to form a surface recess and protrusion along the sipe depth direction and comprising at least two valley portions that are provided facing the at least two first peak portions (80M1, 80M2) and at least one second peak portion that is provided facing the at least one first valley portion (80V1), the first valley portion (80V1) being sandwiched between the two first peak portions (80M1, 80M2) in the sipe depth direction and extending from one end side of the sipe in the extension direction to an other end side of the sipe in the extension direction, a recess depth of the first valley portion (80V1) with respect to the two first peak portions (80M1, 80M2) gradually reducing as progressing from the one end side to the other end side, characterized in that a position of at least one of the two first peak portions (80M1, 80M2) in the sipe depth direction and a position of the first valley portion (80V1) in the sipe depth direction being gradually closer to each other as progressing from the one end side to the other end side, and the first wave-like portion and the second wave-like portion being provided to positions falling within a range of 100% of the entire sipe length along the sipe extension direction. a first sipe wall surface of a pair of sipe wall surfaces (80a, 80b) that face a space of the sipe, the first sipe wall surface comprising a first wave-like portion at each position in an extension direction of the sipe in which the sipe extends on a tread surface, the first wave-like portion being bent in a wave-like shape to form a surface recess and protrusion along a sipe depth direction and comprising at least two first peak portions (80M1, 80M2) and at least one first valley portion (80V1), and a second sipe wall surface of the pair of sipe wall surfaces (80a, 80b) comprising a second wave-like portion at each position in the extension direction of the sipe, the second wave-like portion being bent in a wave-like shape to form a surface recess and protrusion along the sipe depth direction and comprising at least two valley portions that are provided facing the at least two first peak portions (80M1, 80M2) and at least one second peak portion that is provided facing the at least one first valley portion (80V1), the first valley portion (80V1) being sandwiched between the two first peak portions (80M1, 80M2) in the sipe depth direction and extending from one end side of the sipe in the extension direction to an other end side of the sipe in the extension direction, a recess depth of the first valley portion (80V1) with respect to the two first peak portions (80M1, 80M2) gradually reducing as progressing from the one end side to the other end side, characterized in that a position of at least one of the two first peak portions (80M1, 80M2) in the sipe depth direction and a position of the first valley portion (80V1) in the sipe depth direction being gradually closer to each other as progressing from the one end side to the other end side, and the first wave-like portion and the second wave-like portion being provided to positions falling within a range of 100% of the entire sipe length along the sipe extension direction.