Assumption College (Thai: โรงเรียนอัสสัมชัญ) is a Roman Catholic all-boys private school in Bangkok, Thailand.

[4] The institution is named in honor of the Blessed Virgin Mary under the title “Our Lady of the Assumption”.

Assumption College traces its history to 1885, when Reverend Father Emile-August Colombet, a Roman Catholic French missionary priest, opened a school in Bangkok.

Colombet sent a letter to King Chulalongkorn and the queen and solicited contributions and donations from noblemen and Thai and foreign merchants in Bangkok.

On 15 August 1887, Crown Prince Maha Vajirunhis represented King Chulalongkorn in laying the cornerstone for the construction of the first study hall, later named the "old building" (Thai, "tuek gao").

In 1910, the school changed its name from Collège de l'Assomption to Assumption College or AC.

At that time, the Brothers of Saint Gabriel established Assumption College Primary Section in 1965 in Sathon, Bangkok, on an area of six rai.

The school was officially opened and blessed on 6 May 1967 by Archbishop Joseph Khiamsun Nittayo and Mom Luang Pin Malakul.

In 2002, during Brother Surasit Sukchai's term of governance, the English programme (EP) was introduced to serve students who wanted to prepare themselves for international study.

The red and white colors on the coat of arms remind us to honour the nation, religion, and the king.