Marijn Emmanuel Dekkers (born 22 September 1957 in Tilburg, The Netherlands) is a Dutch-American manager and chemist. He was CEO of Bayer AG from 1 October 2010 until 30 April 2016. He was appointed Chairman of Unilever in April 2016. He is also a member of Unilever’s Compensation Committee and the Nominating and Corporate Governance Committee.
Dekkers grew up as the youngest of three children of a merchant in the Dutch city of Tilburg. After attending the local schools, St. Aloysius (primary school) and St. Odulphus (Lyceum), in 1976 he began studying chemistry at the Radboud University in Nijmegen. Three years later he switched to chemical technology at Eindhoven University of Technology, where he received his master's degree and PhD in chemical engineering. From 1985 he worked for General Electric (GE) in research departments in the USA and the Netherlands. In 1988 he was Research Director of the GE range of polymers and subsequently held management positions in various polymer units at GE.
In 1995, Dekkers joined Allied Signal (subsequently Honeywell International Inc.) and took over the management of various business units. In 2000, he became Chief Operating Officer at Boston-based Thermo Electron Corporation, one of the world's leading specialists in the manufacture of laboratory instruments. Within a short time, Dekkers implemented a complete corporate reorganization and became President and CEO in 2002. In this role he initiated further extensive restructuring measures, divesting various organizational units and strengthening the company's core business by means of targeted acquisitions, including the purchase in 2006 of the significantly larger laboratory consumables supplier Fisher Scientific. Dekkers thereby created a company (Thermo Fisher Scientific) with 35,000 employees in six business groups.