From the 1920s, at 27-29 Ham Long, a primary school exclusively for boys was built and opened the first school year. It was the Léonet primary school, set up by the French colonial government. After the August Revolution in 1945, the school changed its name to Ham Long Primary School. In the 70s of the twentieth century, the school changed its name to elementary school, middle school, middle school and now Ngo Si Lien Secondary School, the school named after the historian, national cultural celebrity.

During 100 years of construction and development, Ham Long Primary School - Ngo Si Lien Secondary School has made its mark through many historical stages. It was 25 years of the French colonial rule of Hanoi (1920 - 1945), followed by the months of the pre-insurrection period, of the successful August Revolution, of the first days of building Vietnam. The new South is at the same time the preparation for the resistance war to protect the capital. The school has become a red address with a signboard of historical relics of the revolution and resistance war. During the 9 years of temporary occupation, teachers and students of the school have always quietly participated in patriotic activities, then burst with joy on the Liberation Day of the Capital 10/10/1954. Next is the 45-year journey (1975 - 2020), Hanoi and the whole country go to socialism, actively renewing integration and development...
Reviewing the heroic historical journeys associated with the existence and development of the school to see that under any circumstances, the education sector in the capital, including Ngo Si Lien Secondary School, always inherits and promotes the values ​​of the school. tradition of national education and receiving the educational quintessence of mankind, bringing the quality of education to a new, higher and more modern level. Especially, in more than 20 years of educational innovation, Ngo Si Lien Secondary School has risen, continuously achieved excellent results, becoming one of the leading secondary schools in terms of quality in the city. On the basis of the quality of comprehensive comprehensive education that is continuously improved, the school has risen to new heights in the quality of training excellent students. Ngo Si Lien Secondary School has become a school with great attraction, a reliable address, a place to entrust and fulfill the aspirations of teachers to excel in teaching, to study well for students and, accordingly, to believe in love. of parents when their children are trained to grow up.
From a small school, initially with only a few hundred students, up to now, Ngo Si Lien Secondary School has grown with 2590 students studying in 55 classes and a team of nearly 120 officials, teachers, and staff. energetic and enthusiastic.

Teacher Pham Thu Ha - Rector of the school shared: "Inheriting the historical features of the school and to continue to uphold the tradition of good teaching - good learning, the quality of teachers plays a decisive role. to build a brand and develop the school. 100% of the school's officials and employees meet the academic standards and above the standards. Number of teachers with university degrees: 85% of which there are 28 masters, currently 6 teachers continue to study to improve their qualifications above the standard.