Prince Franz Josef was born at Frauenthal Castle in Styria on 16 August 1906. He was the first son of Prince Alois of Liechtenstein and Archduchess Elisabeth Amalie of Austria. Emperor Franz Josef I was godfather to the little prince.

Prince Franz Josef spent an untroubled youth in various castles across Austria. At Gross-Ullersdorf Castle in Moravia (1911–1914) he developed his passion for nature that influenced his future studies.

In keeping with an education based on Liechtenstein tradition, Prince Franz Josef attended the Schottengymnasium school in Vienna, where he graduated in 1925. His favourite subjects were mathematics, natural history and Greek. His passion of nature led him to continue his studies at the University of Agricultural Sciences in Vienna (1925–1929).

In 1929 Prince Franz Josef graduated from the University as a forestry engineer and then devoted his attention to the administration of the vast estates in Czechoslovakia, which became his responsibility after the death of Prince Johannes II. Skiing and mountain sports as well as swimming were among his favourite leisure time occupations. The young prince often travelled in Europe and overseas.

Prince Franz I passed the regency to Prince Franz Josef on 30 March 1938. On 25 July of that year, Franz I died and the designated Prince Regent took over the affairs of state. The homage of the Liechtenstein people towards its new Prince took place on 30 May 1939.

With the world threatened by the hostility of the Third Reich, this enunciation gained added significance as the people affirmed their statehood under the leadership of their new prince, Franz Josef II. Liechtenstein experienced a second grand event when the Prince married Countess Georgine of Wilczeck (daughter of count Ferdinand of Wilczeck and countess Nora Kinski, born in Graz on 24 October 1921, died in Vaduz on 24 October 1989) on 7 March 1943.

They had five children:
Hereditary Prince Hans Adam (born 14 February 1945),
Prince Phillip Erasmus (born 19 August 1946),
Prince Nikolaus Ferdinand (born 24 October 1947),
Princess Nora Elisabeth (born 31 October 1950)
and
Prince Franz Josef Wenzel (born 19 November 1962, died 28 February 1991).

Prince Franz Josef II directed his entire energy to keeping Liechtenstein out of the World War II. He used speeches from the throne and other pronouncements to strengthen the inner community and resistance of his people.

After the war Franz Josef II dedicated himself mainly to the economic, social and cultural progress of Liechtenstein. The modern and viable Liechtenstein of today is testimony to his success.