Amidst conflicts and pressures, the members of the barangay council of Magugpo Poblacion, through the efforts of Barangay Captain Prospero Estabillo, ratified a Barrio Charter on February 14, 1967 that would address the critical challenges in education for the poor and less affluent families who primarily cannot afford to send their children to private schools. This marked the beginning of the long-term plan of the late Schools Division Superintendent Eulalia B. Basañes to create and sustain a public secondary high school in the capital town of the province. Thus, Tagum Community High School came into existence.

Initially with 68 first year students and 54 second year students, the school opened its doors in June 1967 and Mrs. Basilia Zamora, who was then the in-charge of Tagum District, became its first school administrator until Ms. Gloria M. Gazmen, the longest reigning school principal, assumed office in 1970. In its founding years, the school had only few teachers, in the persons of Mrs. Herminia Selga, Mrs. Aida Jain-Alcid, and Mr. Nalzar Concepcion, together with the part-time teachers, Mrs. Evangeline de la Cruz, Ms. Bagara and Mrs. Susana Theresa B. Estigoy. However, this roster of pioneer teachers was changed due to re-assignment to other schools. But, eventually, the addition of Mrs. Elizabeth Juarez, Mrs. Irenea Bermudez, Mr. Silvestre C. Padilla, Mr. Rolando Castronuevo, and Mrs. Betty Vinson strengthened the school’s pool of educators.

As the community high school slowly gained its footing, Mr. Nalzar Concepcion, one of the teachers, then organized the first Parent Teacher's Association (PTA) which elected Mrs. Rosa Lucero and Mrs. Pelagia Concepcion as president and secretary, respectively.

In March 1970, a remarkable event took place in Tagum Community High School when it held its first graduation rites.

With meager tuition fees, the school could hardly make an upkeep. To alleviate the logistics and financial problems, and to pursue educational progress, a municipal resolution was filed to convert and rename Tagum Community High School to Tagum Municipal High School upon consultation of various stakeholders including the former municipal mayor Herminigildo Baloyo, the Schools Division Superintendent, then Hermogenes Hipolito, the PTA officials, the members of the barangay council led by barangay captain Dionesio Quirante, and barangay secretary Silvestre Padilla. The municipal resolution aimed to help the school to grow by providing locally sourced funds for its development and improvement. Nevertheless, upon the motion of then Vice Mayor Gelacio Gementiza, seconded by Councilors Antonio Lagunzad and Lucio Rallos, Tagum Community High School was converted and renamed to Tagum Municipal High School in 1972. With the help of Mr. Rufino Cabang, the former municipal treasurer, funds were released, and construction of classrooms began.

Since its establishment in 1967, Tagum Municipal High School did not have a land of its own. At first, it was located at the back of the old municipal hall (now Tagum City Historical and Cultural Center). But in 1986, dreaming of a permanent school site, Ms. Gloria Gazmen, in cooperation with Mr. Manuel B. Suaybaguio, Jr., the PTA president, Mrs. Natividad Manzano, Sgt. Antonio Francisco, Sr., and Sgt. Sergio Pendon, Sr., the PTA board of directors and officers, the school acquired its permanent site, a 2-hectare parcel of land situated in Mangga, Barangay Visayan Village which was donated by Mr. and Mrs. Climaco E. Maurillo.

Many have opposed this newly donated land because of its terrain — swampy, muddy, flood-prone, and snake-laden area — which is not ideally conducive for students to learn. Unfazed by these factors, the school administration gradually developed the area to eventually become the city’s most famous and populated school. In 1986, during the superintendency of Prudencio N. Mabanglo and mayorship of Victorio Suaybaguio, Jr., the donated land was formally transferred to the Department of Education, Culture, and Sportss (DECS) with the help of Supt. Teofilo Gomez. The acquisition of permanent site became one of the driving forces in the progressive development of Tagum Municipal High School. In the later years, Tagum Municipal High School would be renamed to Tagum National High School.

Following the proposed augmentation of science and technology in the country, the Department of Science and Technology-Science Education Institute (DOST-SEI) collaborated with Tagum National High School to offer the Engineering and Science Education Project (ESEP). This project, which was later known as Science, Technology, and Engineering (STE) Program, offered a unique curriculum to selected students which focused on enhancing science and mathematics education. By winning numerous academic competitions, as well as, extra-curricular competitions, the school was gradually renowned to provide the best education in the province.

On September 19, 2005, following the assent of the heirs of the late Mr. Climaco Maurillo, the City Government of Tagum ratified the City Ordinance No. 192, renaming Tagum National High School to Tagum City National High School. Much to the school’s gratitude to the land donors, the school gymnasium was thereby named as Climaco E. Maurillo, Sr. Gymnasium to serve as his perpetual memorial.

With the outstanding competence, performance, and leadership of its former principals, Ms. Gloria Gazmen-Tan, Mr. Amadeo Patriarca, Mrs. Victoria P. Balquiedra, Dr. Teodorico S. Caballero, and Dr. Judith P. Magsipoc, the school managed to sustain and improve its credibility and dignity to provide quality education for Tagumeños. Various educational programs have been implemented such as the school-initiated Special Regular Classes (SRC), the Special Program for Foreign Language (SPFL), and Enhanced Curricular Offerings in Sports and Arts. Being all-inclusive, Tagum National High School also opened its doors to learners with special needs through its Special Education program (SpEd).

From its humble beginnings, Tagum National High School soared high with the help of various stakeholders, such as the Local Government Units, Private Sectors, and Non-Government Organizations, who have pledged support and assistance to the school. Notwithstanding, the generous and proactive parents who became lifetime partners in improving the school and the quality of education for the learners. Indeed, Tagum City National High School has grown considerably. At present, the school is recognized as one of the Most Sustained Schools in the annual Brigada Eskwela, with millions of resources generated through the support of all its stakeholders.