The Order of Merit class was established in 1949 by Cardinal Canali, the Grand Master, under the guidance of Pope Pius XII, to honor non-Catholics who would otherwise be excluded from the Equestrian Order. Originally of five classes, mirroring the structure of the Order itself, the constitution of 1977 limited the award to three classes: the Cross of Merit, with the rank of Knight (Dame) Commander; the cross of Merit, with the rank of Silver Star or Grand Officer; and the Cross of Merit, with Gold Star or Knight (Dame) Grand Cross.

The insignia of this special award comprises a ribbon of equal stripes, four white and three red.The insignia itself is a red cross (gallow cross), similar in style to the Jerusalem cross without the four Greek crosses. Surmounted from the top by a golden Crown of Thorns, the insignia is suspended from the ribbon by a simple golden clasp.

The rank of Grand Cross and Knight (Dame) Commander are awarded with a star. For the rank of Grand Cross, the eight-rayed silver star is surmounted by the insignia in full size. For the rank of Knight (Dame) Commander, the insignia surmounted on the star is a smaller, more traditional size.