The government of Kenya encourages Income Generating Activities in educational institutions to generate income for enhancement of the quality of education. Whereas, principals of secondary schools have embraced this approach, little was known on the actual influence of Income generating Activities on quality of secondary school education. To establish the influence of Income generating Activities on the quality of secondary school education in Kenya, Migori County was chosen as the site for the study. Migori County was chosen among 5 counties surveyed because it had the lowest average mean score of 4.530 (D+) and between 2011 and 2017 it varied from C- in 2011 to D in 2017 exhibiting poor quality education. The average national Kenya Certificate of Secondary Education mean score from 2011 to 2017 varied from 5.207 (C-) in 2011 to 5.173 (C-) in 2012 and declined to mean score of D+ between 2013 and 2015. The national Kenya Certificate of Secondary Education mean score dropped to a mean score of 3.980 (D) in 2016 and declined to 3.734 in 2017 resulting in an average national mean score of 4.617 (D+) over a seven year period which indicated declining quality education. The objective of this study was therefore to establish the influence of income generating activities on quality of secondary school education in Migori County, Kenya. The study established that Income Generating Activities accounted for 50.7% of the variation in the quality of secondary school education. This implies that income generating activities can be relied upon in improving the quality of secondary school education. Thus the income generated is used to promote institutional inputs, for instance provision of teaching /learning resources, physical facilities and human resource.