The exhaust gas cleaning catalyst according to the present invention is provided with a cylindrical substrate 10 and a catalyst coat layer 20 formed on the surface of the substrate 10. A ratio of the length L in the cylindrical axis direction of the substrate 10 and the diameter D of a cross section orthogonal to the cylindrical axis direction is denoted by (L/D)≤0.8. The coat density of the catalyst coat layer 20 differs between an upstream side portion 10a that includes the exhaust gas inlet-side end 16 of the substrate 10 and a downstream side portion 10b that includes the exhaust gas outlet-side end 18 of the substrate 10. The coat density A in the upstream side portion 10a is lower than the coat density B in the downstream side portion 10b (A