Mr William Tan Seng Koon sits on the Boards of SMRT Corporation Ltd and SMRT Trains Ltd. 

Mr Tan is an independent non-executive Director of SembCorp Marine Ltd.

Mr Tan was the President & Chief Executive Officer of SIA Engineering Company for 14 years until he retired in 2015. He has held several senior positions in his 37-year career in the Singapore Airlines Group and has held Chairmanship and Board Directorships in several international companies.

Mr Tan is a Fellow of the Academy of Engineering Singapore, Institute of Engineers and Singapore Institute of Aerospace Engineers. He graduated from University of Singapore with a Bachelor of Engineering in 1976.