The 46-year-old politician fell ill in November last year and was admitted to the Federal Medical Centre, FMC, Idi-Aba, Abeokuta in Ogun State, before he was referred to the University College Hospital in Ibadan.
He was said to have died on Monday after an operation.
The nature of his ailment and cause of death has not been made public.
Mr. Odusanya, before his sudden demise, was a onetime governorship candidate in Ogun State under the Community Party of Nigeria, CPN, in the 2007 general election.
He became the National Chairman of Peoples Party of Nigeria in August 2010. The PPN has its major strength in Ogun where it is funded by the immediate past governor of the state, Gbenga Daniel and won a few electoral seats.
Mr. Odusanya attended Ogun State University, Ago-Iwoye for his first degree. He got a Masters degree from the University of Agriculture Abeokuta, UNAAB. He hails from Ilodo, Ijebu-Mushin, in Ijebu-East Local Government Area of Ogun State.
The deceased left behind a wife and three children.