Hereditary Prince Alois was born in Zurich on 11 June 1968 as the eldest son of Prince Hans Adam II and Princess Marie of Liechtenstein and was christened Alois Philipp Maria. This name was given to the Prince in memory of his great-grandfather, Prince Alois of Liechtenstein, the father of then reigning Prince Franz Josef II.

Hereditary Prince Alois spent his youth at Vaduz Castle. He attended primary school in Vaduz-Ebenholz, and he entered the Liechtenstein Gymnasium (high school) in 1979. He graduated in the spring of 1987 (high school diploma type B, with an emphasis on literary history).

He subsequently entered the Royal Military Academy at Sandhurst in the United Kingdom, where he completed his officer's training. On receiving his commission as second lieutenant, he served for six months with the Coldstream Guards in Hong Kong and London.

In October 1988, Hereditary Prince Alois enrolled as a student of law at the University of Salzburg. He completed these studies in the spring of 1993 with a master's degree. From September 1993 to May 1996, he worked at a London auditing company. He then moved back to Vaduz, where he is now responsible for various parts of the Princely assets.

As the eldest son of the Reigning Prince, Hereditary Prince Alois is designated successor to the throne by the Law on the Princely House. On 15 August 2004, H.S.H. Prince Hans Adam II entrusted his son Hereditary Prince Alois as his representative with the exercise of all sovereign rights pertaining to him, in accordance with the Liechtenstein Constitution.

On 3 July 1993, Hereditary Prince Alois of Liechtenstein married Duchess Sophie in Bavaria. They have four children:

• Prince Joseph Wenzel, born 24 May 1995
• Princess Marie Caroline, born 17 October 1996
• Prince Georg, born 20 April 1999
• Prince Nikolaus, born 6 December 2000.