Mads Ovlisen has been Chairman of the Board of Directors of LEGO A/S since 1996, after becoming a Board member in 1990. Since 2006 Ovlisen is member of The United Nations Global Compact Board, New York. He is also, since 2007, Chairman of the Danish Arts Council and a member of the Board of Directors of the Wanas Foundation, Sweden. In addition, he holds the position of adjunct professor of corporate social responsibility at the Copenhagen Business School. Mads Ovlisen served as chairman of The Copenhagen Center for Social Responsibility and was a founding Co-chair of the European Academy for Society in Business(EABIS). 2000-2007 Ovlisen also was the Chairman of the Board of Directors of the Danish Royal Theatre.

Mads Ovlisen started his career with Novo Industri A/S in 1972. In 1975, he became a member of corporate management and was president and CEO of Novo Industri A/S from 1981-1989, then of Novo Nordisk A/S from 1989-2000. He was also a member of their boards, becoming Chairman in 2000. Mads Ovlisen was also board member of the Novo Foundation, 1982-1989, and of the Novo Nordisk Foundation starting in 1989. He decided to resign from the Board of Governors of the Novo Nordisk Foundation in April 2006 after having retired as Chairman of the Board of Directors of Novo Nordisk A/S.