In the 1980s, he worked as an underground publisher and conspirator and was also awarded the Officer’s Cross of the Order of the Rebirth of Poland by the President. He authored numerous articles about Poland, published in the underground press and the West. Additionally, he was honored with the SDP Po Prostu Award for editing the Metrum magazine.

From 1989 to 1996, he resided in the USA, where he served as the editor-in-chief of the Polish-American Daily and the Courier and later ran a marketing agency.

Upon returning to Poland, he assumed the position of Sales Director at RMF FM Radio. Subsequently, in 1997, he founded the training company Midwest ITSE, and in 2000, he established the MMT Management agency. For many years, he personally conducted hundreds of training sessions on sales, sales management, and communication. From 2005 to 2014, he was a member of the Board of the Adam Smith Center.

In 2010, he founded the Union of Entrepreneurs and Employers, of which he is the president. He also serves as the chairman of the Supervisory Board of the Warsaw Enterprise Institute. Since 2018, he has held the position of Deputy Chairman of the Social Dialogue Council.

In 2006–2007, director of the Investor Acquisition Department at the Łódź Special Economic Zone S.A. In 2008–2009 he was the director of the Entrepreneurship Department at the Marshal’s Office in Łódź (Regional Government). He participated in the management of over 40 investment projects with a total value exceeding EUR 1 billion. Marcin has been involved in the Union of Entrepreneurs and Employers (ZPP) since 2011. Today ZPP belongs to the group of three largest employers’ organizations in Poland.

As part of the ZPP, he coordinates corporate and sectoral relations departments. Marcin also oversees all foreign relations and partnerships, including the ZPP Representation in Brussels, participating in critical regulatory processes for Polish entrepreneurs in the EU. Initiator and head of the European Enterprise Alliance, an organization of entrepreneurs registered in Brussels associating with organizations of employers from Central and Eastern Europe.

A graduate of international relations at the Faculty of International and Political Relations of the University of Lodz, a scholarship holder at universities in England, France, and China. In 2009-2012 he was the chairman of the Alumni Association of his Faculty at the University of Lodz. For many years active in the movement of think tanks in Europe and the United States. A graduate of the Atlas think-tank MBA program. Marcin has been a member of the Social Dialogue Council (RDS) since 2018 and has been a member of the European Economic and Social Committee (EESC) since September 2020.

In 2022, Marcin was honored with the Steven M. Sass Economic Freedom Award by the Heritage Foundation. In April 2023, Marcin Nowacki assumed the role of Chairman of the EU-Ukraine Civil Society Platform in Brussels.