Mohd Shamsudin bin Lias (Jawi: محمد شامس الدين لياس, Malay pronunciation: [mohamad shamsudin]; born 15 December 1953) is a Malaysian politician who served as the Leader of the Opposition of Selangor from June 2013 to his resignation in December 2014 and Member of the Selangor State Legislative Assembly (MLA) for Sungai Burong from March 2004 to August 2023.

He is a member of the United Malays National Organisation (UMNO), a component party of the Barisan Nasional (BN) coalition.

He is currently living with his family in Tanjong Karang, Selangor Darul Ehsan.

[1] Shamsudin has a master's degree in Urban and Regional planning from Syracuse University in New York State, USA.

[2] In 2010, Shamsudin was appointed as Chairman of the Public Accounts Committee (PAC) even though the state of Selangor was governed by Pakatan Rakyat (PR) and he was a member of Barisan Nasional (BN) which was opposing PR.