In the private sector Yeo has chaired numerous company boards, including: Singapore Technologies Holdings, Sembawang Corporation, and CapitaLand. Yeo was board member (from 1980) and Chairman of the Executive Committee of Singapore Technologies Holdings from 1987 to 1993. He also served as Chairman of Sembawang Corporation (1994–1998) and the successor Sembcorp Industries (1998–1999), Pidemco Land (1999–2000) and CapitaLand (2000–2003) formed from Pidemco after a merger in 2000. Yeo is currently the Chairman of a-iTrust (Ascendas India Trust – Asia's first listed India property trust) and Accuron Technologies. In addition, he is a non-executive director on the board of directors of City Developments Limited, and was appointed as one of the first non-Japanese outside directors of Hitachi alongside George Buckley, the former chief executive officer of 3M. In 2013, Yeo joined the board of directors of the Baiterek National Managing Holding of Kazakhstan, which is a trust management company which manages key Kazakh financial institutions like the Development Bank of Kazakhstan. In December 2013, Yeo joined the Board of Kerry Logistics in Hong Kong. In April 2020, Yeo joined the Board of Sunway Berhad.