Retirement is inevitable in the life of every teacher and failure to prepare effectively based on relevant information usually lead to poor preparation that some may regret later in life. To avoid this challenge, this study examined retirement education as correlate of old age preparedness among public Secondary School teachers in Oyo State. The study adopted the descriptive research design of the survey type and the sample was made up of 383 teachers from 43 public secondary schools in Ibadan South West and North West Local Government Areas of Oyo State based on the criteria that such teachers are above 50 years of age in addition to those who are already due for retirement as well as those already processing their retirements. Two research instruments titled “Retirement Education Questionnaire (r = 0.85)” and “Old-Age Preparedness Questionnaire (r = 0.72)” were used for data collection. Mean and standard deviation were used to answer research questions while hypothesis was tested using Pearson Product Moment Correlation (PPMC) at 0.05 level of significance. Results show that retirement education is a correlate (Average Mean = 2.51) of old-age preparedness; teachers face various challenges related to retirement processing, and; there is a positive correlation (r = .141, p=0.037 < 0.5) between retirement education and old-age preparedness among teachers. It was recommended that employers should make it part of their routines to engage retiring teachers in seminars, workshops and related activities which might help the teachers to make concerted efforts toward preparing effectively for retirement.