A rolling bearing for a rocker arm includes an outer ring in rolling contact with a cam of an engine, an outer-ring shaft placed inside the outer ring and fixed to the rocker arm, and a plurality of rollers provided between the outer ring and the outer-ring shaft. At least one of the outer ring, the outer-ring shaft and the rolling elements has a nitrogen-rich layer, an austenite crystal grain size number in a range exceeding 10, and a surface hardness Hv of at least 653. Thus, the life can be extended.