To provide a flue gas NOx removal catalyst which enables a prevention of a catalyst degradation with phosphorus.

The flue gas NOx removal catalyst is a NOx removal catalyst to remove nitrogen oxides from the flue gas, and has a coating layer of calcium silicate on an end surface of a flue gas inflow side of the catalyst. The NOx removal catalyst is a molding comprising a composition containing, for example, one or more oxides selected from titanium, tungsten, molybdenum, and vanadium. The flue gas NOx removal system carries out a catalytic-reduction of nitrogen oxides contained in the flue gas containing a phosphorus compound by using the catalyst.