A speaker disposition structure of a vehicle, the speaker disposition structure comprising: a hinge pillar extending in a vehicle up-down direction; a side sill fixed to a lower end of the hinge pillar and extending in a vehicle front-rear direction; a speaker box that holds a speaker and is fixed to the hinge pillar in a vicinity of the side sill; and a gap for arranging a vehicle component at an upper part of a vehicle-interior side of the side sill, the speaker box includes: an outer-box part; an abutting part abutting the hinge pillar; an upper space forming portion that bulges inward in a vehicle width direction from the abutting part above the gap and that holds the speaker; and an extended space forming portion that extends downward from the upper space forming portion and is adjacent to a vehicle-width-direction inner side of the gap, wherein the upper space forming portion and the extended space forming portion are arranged next to one another in an up-down direction and together confine a closed space, and the extended space forming portion is formed such that a vehicle-width-direction dimension in a cross section orthogonal to the vehicle front-rear direction is smaller in a lower portion of the extended space forming portion than in an upper space forming portion of the extended space forming portion, a first opening is formed at an inner wall of an hinge pillar inner, preferably at a middle portion in the up-down direction of the hinge pillar inner, and a second opening for attaching the outer-side box part of the speaker box is formed at a lower portion of the inner wall below the first opening. a hinge pillar extending in a vehicle up-down direction; a side sill fixed to a lower end of the hinge pillar and extending in a vehicle front-rear direction; a speaker box that holds a speaker and is fixed to the hinge pillar in a vicinity of the side sill; and a gap for arranging a vehicle component at an upper part of a vehicle-interior side of the side sill, the speaker box includes: an outer-box part; an abutting part abutting the hinge pillar; an upper space forming portion that bulges inward in a vehicle width direction from the abutting part above the gap and that holds the speaker; and an extended space forming portion that extends downward from the upper space forming portion and is adjacent to a vehicle-width-direction inner side of the gap, an outer-box part; an abutting part abutting the hinge pillar; an upper space forming portion that bulges inward in a vehicle width direction from the abutting part above the gap and that holds the speaker; and an extended space forming portion that extends downward from the upper space forming portion and is adjacent to a vehicle-width-direction inner side of the gap, wherein the upper space forming portion and the extended space forming portion are arranged next to one another in an up-down direction and together confine a closed space, and the extended space forming portion is formed such that a vehicle-width-direction dimension in a cross section orthogonal to the vehicle front-rear direction is smaller in a lower portion of the extended space forming portion than in an upper space forming portion of the extended space forming portion, a first opening is formed at an inner wall of an hinge pillar inner, preferably at a middle portion in the up-down direction of the hinge pillar inner, and a second opening for attaching the outer-side box part of the speaker box is formed at a lower portion of the inner wall below the first opening.