Stephen Kalonzo Musyoka (born 24 December 1953) is a Kenyan politician who was the tenth Vice-President of Kenya from 2008 to 2013.
Musyoka served in the government under President Daniel arap Moi and was Minister for Foreign Affairs from 1993 until 1998; subsequently, under President Mwai Kibaki, he was Minister of Foreign Affairs again from 2003 to 2004, then Minister of the Environment from 2004 to 2005.
He was an unsuccessful candidate in the 2007 presidential election, after which he was appointed as Vice-President by Kibaki in January 2008.
Musyoka is the party leader of the Wiper Democratic Movement (formerly Orange Democratic Movement-Kenya).
He also serves as Chief Commissioner for The Kenya Scouts Association.