The Illustrious Royal Order of Saint Januarius (Italian: Insigne Reale Ordine di San Gennaro) is a Roman Catholic order of knighthood founded by Charles VII of Naples in 1738.

It was the last great dynastic order to be constituted as a chivalric fraternity, with a limitation to Roman Catholics and a direct attachment to the dynasty rather than the state.

The grand magistery of the order is disputed among claimants to the headship of the formerly reigning House of Bourbon-Two Sicilies.

Since 1960, the order has been awarded sparingly and total membership has not exceeded eighty, most of the knights being members of royal houses, senior officers of the Sacred Military Constantinian Order of Saint George, or Italian grandees.

As of 2016[update], the knights appointed by Prince Pedro, Duke of Calabria, his father and grandfather, were: As of 2014[update],[2] the knights appointed by Prince Carlo, Duke of Castro, his father and grandfather, were: