Johann I Joseph (Johann Baptist Josef Adam Johann Nepomuk Aloys Franz de Paula; 26 June 1760 – 20 April 1836) was Prince of Liechtenstein between 1805 and 1806 and again from 1814 until 1836. He was the last Liechtenstein prince to rule under the Holy Roman Empire between 1805 and 1806 and as regent of Liechtenstein from 1806 until 1814. He was the fourth son of Franz Joseph I, Prince of Liechtenstein.

Liechtenstein chose a military career at age 22 and entered the army as a lieutenant in a cuirassier regiment. During the Austro-Turkish War (1787-1791) he earned, in rapid succession, promotion to Major, Oberstleutnant, and Oberst (colonel). He earned renown as a good cavalry officer and was honored with the Knight's Cross of the Military Order of Maria Theresa in 1790.

During the French Revolutionary Wars, he participated in an "outstandingly effective cavalry action" at Avesnes-le-Sec on 12 September 1793, where 4,663 Republican troops suffered losses of 2,000 killed and wounded with the Allies losing only 69 men. In addition, 2,000 soldiers and 20 artillery pieces were captured. He also participated in many other battles. Soon after being promoted to General-Major in June 1794, he fought at the Battle of Fleurus. He commanded a mixed cavalry-infantry brigade in Anton Sztaray's division at the Battle of Würzburg on 3 September 1796. After this action he was awarded the Commander's Cross of the Order of Maria Theresa.

In the War of the Second Coalition, Liechtenstein commanded the Austrian Reserve at the Battle of Trebbia. In August 1799 he received promotion to Feldmarschal-Leutnant. He commanded 8,000 men in the successful siege of Cuneo in November and December. On 3 December 1800, he led a 5,109-man cavalry division in the Battle of Hohenlinden.

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