In April 2003, Ọlagunsoye Oyinlọla was elected governor of
Osun State as a member of the ruling
People's Democratic Party (PDP). He was reelected in April 2007. In an interview in November 2003, Ọlagunsoye Oyinlọla spoke in favor of increased education in
Yoruba, even up to the university level. When asked about the
Afenifere movement, he stated that he would join if it were purely an association of Yorubas, but not if it was just another name for the
Alliance for Democracy (AD) party. After the 2007 election, the
Action Congress governorship candidate,
Rauf Aregbesola filed a petition with the
Independent National Electoral Commission (INEC) against his victory. The tribunal rejected his petition. Aregbesola appealed the decision, leading to a fresh hearing in June 2009. In April 2009,
Next magazine reported that Olagunsoye Oyinlola had been caught on tape telling local PDP politicians he would supply army uniforms, arms and ammunition so they could rig the runoff elections in
Ekiti State. In July 2009, Olagunsoye Oyinlola banned
Igbo people in Osun state from parading themselves as Eze Ndigbo (king of Igbo), in order to protect the Igbo culture and traditional institution from ridicule. At the same time, he sought constitutional responsibilities for traditional rulers in the country. In September 2009, Oyinlola opened a ceremony at which Modakeke traditional ruler, Oba Francis Adedoyin, was crowned. On 26 November 2010 the Court of Appeal in Ibadan presided over by Justice Clara Ogunbiyi ruled that Oyinlola had not won the 2007 election and that the Action Congress candidate
Rauf Aregbesola should be sworn in as governor. He is a former chairman of the board of the National Identity Management Commission (NIMC) having been appointed in 2017. On 31 January 2018, he was part of the launch of "Coalition for Nigeria" movement a political movement to check the failings of APC. ==Appointment as NIMC's Chairman Board of Directors==