He announced his defection shortly after his inauguration as Speaker.
Oloyelogun said that he would be decamping officially with some other members on Tuesday.
He said: "We are here today to signify our intention to join the ruling party, APC. The other ceremony will be done tomorrow (Tuesday).
"At the national level, they have factionalized our party. The same scenario is also at the state level. This declaration is for our followers and those we represent.
"We are ready to work with the executive without any problem, and all necessary things to be done are in place. Be rest assured that Gov. Rotimi Akeredolu is ready to work and we are ready to support him."
Similarly, the Deputy Speaker, Ogundeji Iroju said PDP was on the verge of dying; adding that it was the APC that could deliver good governance to the people of the state.