This absorbent article minimizes contact between a wearer's skin and places in a leak prevention wall that are anchored by heat welding. An absorbent article (1) comprises an absorbent body (AB), a pair of side flaps (7, 7), and a pair of leak prevention walls (5, 5), and comprises an expansion/contraction member (11) that is joined to the absorbent body between the pair of side flaps and can expand and contract in a width direction. Each of the pair of leak prevention walls includes a standing section (5c), the outer side of which in the width direction is an anchored end and the inner side of which in the width direction is a free end, and a support section (5b) that is adjacent to one end section of the standing section in a lengthwise direction and overlaps with the expansion/contraction member in a thickness direction. Each support section (5b) includes an inner side section (5SI) that is positioned to the inner side in the width direction and is not anchored to the absorbent body, and an outer side section (5SO) that is positioned to the outer side in the width direction and is anchored to the absorbent body at a heat weld section (50).
