Stephan Harbarth (born 19 December 1971 in Heidelberg) is the president of the Federal Constitutional Court of Germany (Bundesverfassungsgericht), former German lawyer and politician of the Christian Democratic Union (CDU).

From 2016, Harbarth served as deputy chairman of the CDU/CSU parliamentary group, under the leadership of successive chairmen Volker Kauder (2016-2018) and Ralph Brinkhaus (2018).

In this capacity, he coordinated the group's legislative activities on consumer protection, domestic affairs, sports, and minorities.

In the negotiations to form a coalition government under the leadership of Chancellor Angela Merkel following the 2017 federal elections, he was part of the CDU delegation.

Aled Wyn Griffiths, editor-in-chief of JUVE Verlag für juristische Information stated his "honest amazement"[5] that a discussion about Harbart's eligibility for election was being held at all.

Griffiths added: "If these questions were asked of a member of the Supreme Court in the UK or the US, the reaction would be one of honest amazement.

In 2019, two members of the German Parliament filed an action for a declaratory judgment with the Federal Constitutional Court, seeking a declaratory judgment that the election and appointment of Harbarth as a judge of the Federal Constitutional Court was null and void:BVerfG, decision of 2 July 2019 - 2 BvE 4/19.

[10] The core of the applicants' argumentation was, according to the summary of the Federal Constitutional Court in the reasons for its decision: "Irrespective of this, there is a deliberate violation of the provision of § 44a of the AbgG that is laid down by simple statute, because the respondent in the second place did not disclose that the Vice-President of the Federal Constitutional Court, in his time as a Member of Parliament, had received substantial, probably overwhelming, property allocations from third, unsettled sources.

He had therefore disregarded Paragraphs 44a and 44b of the AbgG; at the same time, the information which he had provided in an obviously concealing manner had not been verified by the respondent in the second place and had therefore been deliberately mispublished.

The untruthful information and the deficiencies in disclosure also led to a violation of Article 97.1 of the Basic Law and the principle of democracy.

Nevertheless, the leading German constitutional legal scholar Michael Sachs was "irritated that [the court] has taken it for granted that the influence of deliberate misinformation or failure to inform is subsumed under the concept of coercion.

"[12] Whether the Federal Constitutional Court had at the time of its decision the files of the Bundestag administration with their audit report on Harbarth and § 44 a AbgG at hand is unknown.

Other media also reported that Harbarth worked in a big law firm where the Cum-Ex tax models were first invented.