Vincent Nguyen, also known as Vincent Nguyễn Mạnh Hiếu (born Nguyễn Mạnh Hiếu on May 8, 1966) is an auxiliary bishop of the Archdiocese of Toronto.

On November 6, 2009 Nguyen was appointed by Pope Benedict XVI as one of two new Auxiliary Bishops for the Archdiocese of Toronto along with Bishop William McGrattan.

He holds a Bachelor of Applied Science in electrical engineering from the University of Toronto and a Masters of Divinity from St. Augustine's Seminary in Toronto.

He then did further studies in Rome, where he received a licentiate in canon law from the Angelicum.

From September 2009 to his consecration as bishop, he served as Chancellor and Moderator of the Curia of the Archdiocese of Toronto.