Gatunga boys secondary school was established in 1972 on a construction site by an Italian company known as Compressor Abenalco. The provincial station requested the company's leaders to allocate some rooms for the establishment of a school. In conjunction with the Father in charge of Gatunga Parish, now part of the Catholic Diocese of Meru, they were granted two rooms to start the school. In 1973, students enrolled in this mixed school, which operated as a harambee school. Initially, the head teacher oversaw both primary and high school levels. Subsequently, the provincial administration and other stakeholders formed a school committee. The school transitioned to a boys' school in 2004. In 2020, it became the precursor to Tharaka University, hosting the Tharaka University campus on its land.

It has been a cornerstone of education in Tharaka South Sub-County, Tharaka Nithi County, Kenya. Over the years, the school has evolved into a hub of academic excellence and character development, shaping the lives of countless students who have walked through its doors. With a commitment to nurturing young minds and empowering future leaders, Gatunga Secondary School continues to uphold its legacy of providing quality education and fostering a supportive learning environment for generations to come.