His father Jan Omtzigt (1939-2019) was a civil servant at the Dutch state telecommunications company PTT and later director of a Roman Catholic retirement house in Zenderen.

He performed his doctoral research at the European University Institute (Florence, Italy), where he obtained a PhD in Economics in 2003, with the dissertation titled Essays in Cointegration Analysis.

In the end, civil servants and (former) ministers were heard by the parliamentary questioning committee on Childcare Allowance, which ultimately led to the fall of the third Rutte cabinet in January 2021.

In July 2020, Omtzigt was defeated by Deputy Prime Minister Hugo de Jonge in a vote for the position of leader of the Christian Democratic Appeal.

[17] On 20 August 2023, Omtzigt announced his participation in the early Dutch parliamentary elections scheduled for 22 November 2023, with the party New Social Contract (NSC).

As part of the cabinet formation, Omtzigt entered talks under informateur Ronald Plasterk with the PVV, VVD, and BBB to address those concerns.

[23] During Omtzigt's absence, Van Vroonhoven negotiated a deal on asylum measures, and she averted a cabinet collapse following the resignation of State Secretary Nora Achahbar due to "polarizing interactions".

[25][26] Omtzigt started a phased return to the House in late November, and he would temporarily share the role of parliamentary leader with Van Vroonhoven.

[27][28] Omtzigt froze and walked out of a December 2024 interview with Rick Nieman [nl] after being asked about his reported emotional behavior during formation talks, but returned shortly after to continue.

[29] In addition to his role in parliament, Omtzigt has been serving as member of the Dutch delegation to the Parliamentary Assembly of the Council of Europe (PACE) since 2004.

[31] Omtzigt has also served as rapporteur on the case of the car bombing of journalist Daphne Caruana Galizia (2018),[32] justice for the victims of ISIL (2019);[33] and on Poland (2019).

He has been critical of European Central Bank policies and, in 2020, pushed his party to support the idea of the Netherlands opting-out of unwanted EU programs.

[36] During the campaign for the 2023 Dutch general election, Omtzigt positioned himself as a centrist: conservative on immigration and climate change but leftist on reducing poverty and improving healthcare.

[37] At EW's 2024 HJ Schoo speech, Omtzigt advocated for a social market economy, arguing that the role of the national government should be enlarged.

The man, who was an asylum-seeker from Ukraine, never witnessed the crash, and his speech, texted to him by Omtzigt prior to the interview, repeated one of the Russia-promoted versions of Mig jets downing the Boeing.