Johann Maximilian von Welsch (1671 – 15 October 1745) was a German architect, High Director of Building and fortress master builder.
Maximilian von Welsch is regarded as a prominent representative of baroque fortress building in the Holy Roman Empire. Besides this he got reputation with the construction of several palaces.
Maximilian was born in Kronach, belonging to the Prince-Bishopric of Bamberg at that time. He studied construction during his early education journeys mainly to European capitals such as Vienna, Rome and Paris. There he studied the buildings of Johann Bernhard Fischer von Erlach, Francesco Borromini and François Mansart.
Since 1695 he was in imperial military service and as a military engineer responsible for the construction of fortresses. In 1704 the Archbishop of Mainz Lothar Franz von Schönborn recognised his good reputation and employed Welsch for the upgrading and extension of the fortress Mainz. In Mainz he was not only responsible for the construction of the fortress, but Lothar Franz von Schönborn assigned him also with the architectural design of his summer residence Favorite opposite the confluence of the Main river with the Rhine. Von Welsch was the responsible civil engineer and master builder of this place. In 1793 the Favorite was destroyed by the Prussians during the Siege of Mainz.