The governing authority of the IOSH is the Grand Master, currently Istvan von Habsburg-Lothringen. He is assisted by a staff or ‘Grand Chapter’ which he selects; the nominal headquarters of the Grand Chapter is the principal residence of the Grand Master.

The Grand Chapter is composed of four Dignitaries: the Chancellor, the High Justice, the Secretary and the Treasurer. The Grand Priors of the national chapters also serve as members of the Grand Chapter. The present Grand Priors are Jeff Parsons, United States; Cosme Maria Beccar Varela, Argentina; Siegfried Birngruber, Austria; Dirk van Gheluwe, Belgium; Tommy Leland, Canada; Edward King, England; Graziel d'Estalenx, France; Christopher Harms, Germany; Francesco Lombardo, Barone di San Chirico, Italy; Lambert Dupong, Luxembourg; Jose Lopez Rodriguez, Mexico; Christian de Maes Janssens, Netherlands; Jose Manuel Silva e Costa, Portugal; Catalin Grigorescu, Romania; Alfonso Patiño Muguiro, Marqués del Castelar, Spain; and Philipp Kujumdshiev, Switzerland. The Grand Master appoints up to three Councilors who advise him on specific matters.

Additional national chapters are in the process of formation in the Czech Republic and Scotland. While the recent rate of expansion sounds substantial, this is not the case as new chapters begin with a small nucleus and only slowly add membership until independent status finally is achieved.

The composition and functions of the Grand Chapter are defined in the Constitution of the IOSH which was adopted at the time the Order was reestablished, May 1950, in Vienna, Austria. The Constitution was amended in November 2023 in Luxembourg and today regulates the Order of St. Hubertus as the fraternity was first named when founded by Count Anton von Sporck in 1695.