A vehicle seat with a height adjustable seat bottom, comprises side frames (30) which constitute the seat bottom, front links (5) and rear links (6) pivotally connected to the side frames (30), slide rails (4) disposed under the side frames (30) to form a four-bar linkage with the side frames (30), the front links (5) and the rear links (6), and an operation unit (7) including an operation knob (71 B) configured to be operated to make a rotational motion which actuates the four-bar linkage for adjustment of a height of the seat bottom. The operation unit (7) includes a pinion gear (73) configured to be rotatable coaxially with the operation knob (71B) provided at one of the pair of side frames (30), and the front links (5) include a sector gear portion (51) configured to engage with the pinion gear (73), such that rotation of the pinion gear (73) causes the front links (5) to pivot.