A light source apparatus includes first and second optical elements, a support member to which the elements are fixed and supported, a first heat dissipation member to which the first optical element is connected, a second heat dissipation member to which heat of the second optical element is transferred, a heat transport member transporting the heat of the second optical element to the second heat dissipation member, and a cooling fan sending a cooling gas to the first and second heat dissipation members. The first heat dissipation member is on the opposite side from the direction toward which the light outputted from the first optical element travels. The second heat dissipation member is adjacent to the first heat dissipation member with a gap. The second heat dissipation member overlaps with the first heat when viewed along a flow direction of the cooling gas sent thereto.