Leonard Clemence "Leo" Tindemans (Dutch: [ˈleːjoː ˈtɪndəmɑns] ⓘ; 16 April 1922 – 26 December 2014) was a Belgian politician.

[2] In 1968 Tindemans became minister tasked with the relations between the communities (1968–1972) during which he prepared the first constitutional reform which saw Belgium start transforming into a federal state.

At the conclusion of the Paris Summit in 1974, Tindemans was tasked with devising a report to define what was meant by the term 'European Union.

[4] Tindemans deliberately sought to avoid using the term constitution, and instead referred to his proposals as "a new phase in the history of the unification of Europe which can only be achieved by a continuous process".

[4] In regards to a common foreign policy, Tindemans argues that Europe must present itself united outward not only in security, tariffs and trade, but also in an economic sense.

He advocated for the creation of a single decision-making centre to handle these issues, and making foreign policy cooperation between member states a legal obligation – Tindemans felt that this role largely would lie within a strengthened Council.

[4] Tindemans supported abolishing the remaining obstacles to free trade of capital that existed within the European Economic Community.

[5] In the 1970s he was a regular Le Cercle participant (Johannes Grossmann, Die Internationale der Konservativen, München 2014, p. 473).

With the general elections of 1981 Tindemans returned to the Belgian politics and became minister of foreign affairs (1981–1989).