There is described a vehicle seat suspension mechanism, comprising a vehicle mount, a seat support linked to the vehicle mount by a suspension arrangement which allows the seat support to fall with respect to the vehicle mount under load and a shock strut arranged to resist the seat support falling with respect to the vehicle mount during a compression stroke. A control link is arranged to be driven about a control link pivot by the fall of the seat support. The control link is pivotally coupled to a first end of the shock strut to guide the first end with respect to a second end of the shock strut in a manner which causes a motion ratio of the suspension mechanism to increase during progression of the compression stroke. The ride will feel softer for smaller impacts and better damped later for larger impacts. The mechanism is arranged underneath a seat of a vehicle to provide additional comfort for the rider.