The aged man's 26-year-old neighbour was also arrested for the same offence.
A 77-year-old man, Adedamola Idowu, has been arrested by the police in Ogun State for allegedly raping his seven-year-old daughter.
Mr Idowu's 26-year-old neighbour, Oluwatobi Adebisi, was also arrested for the same alleged crime.
The police said the two were arrested Friday at Ijagun, in Ijebu-Ode.
The Police Commissioner, Abiodun Alamutu, paraded the suspects at the police headquarters in the state in Eleweran, Abeokuta, on Tuesday.
Mr Alamutu said he has referred the case to the State Criminal Investigation Department (SCID) for further investigation, while the victim had been referred for emotional therapy.
"This randy father and his neighbour have been having unlawful carnal knowledge of his seven-year-old girl.
"The victim has been referred for counselling and emotional therapy, and the case has been transferred to SCID for discreet investigation and prosecution," he explained."
At the event, the police chief also announced a one-month grace for cultists in the state to surrender arms and ammunition in their possession.
He warned that the police would clamp down on suspected cultists across the state from the end of the period.
"However, we are aware that some people were lured into cultism without knowing the implication, and so they got trapped.
"The Command has opened a window of amnesty to such people. So, they should renounce their membership of these groups and surrender all arms and ammunition in their custody.
"The Command will not fold its arms while some unscrupulous elements will be making life unbearable for the good and law-abiding indigenes and residents of Ogun State," the police chief said.