Hwa Chong Institution (HCI) is an independent secondary educational institution in Bukit Timah, Central Region, Singapore. It was established in 2005 by the merger of The Chinese High School (1919–2005) and Hwa Chong Junior College (1974–2005).

HCI provides secondary education for boys only from Years 1 to 4, and pre-university education for both boys and girls in Years 5 and 6. Since 2005, HCI and its affiliated school Nanyang Girls' High School have offered a six-year Integrated Programme (IP), which allows students to skip the Singapore-Cambridge GCE Ordinary Level (O-Levels) examinations and proceed to take the Singapore-Cambridge GCE Advanced Level (A-Levels) examinations at the end of Year 6. HCI operates under the Special Assistance Plan (SAP) and offers the IP and the Gifted Education Programme (GEP). Its name "Hwa Chong" ("Hua Zhong" or "华中") is an abbreviation of The Chinese High School's Chinese name, "Hua Qiao Zhong Xue" or "华侨中学".

Previously two separate but affiliated schools — The Chinese High School and Hwa Chong Junior College – HCI was established via a merger on 1 January 2005. It was among the first batch of schools to offer the six-year Integrated Programme, which leads directly to the Singapore-Cambridge GCE Advanced Level examinations at the end of the sixth year. In spite of the merger, the High School section remains boys-only. The College section remains co-educational; its Integrated Programme cohort consists of boys from Hwa Chong's High School section as well as girls from Nanyang Girls' High School.

The Chinese High School was founded by Tan Kah Kee in March 1919 at Niven Road, as the Singapore Nanyang Overseas Chinese Middle School (traditional Chinese: 新加坡南洋華僑中學; simplified Chinese: 新加坡南洋华侨中学). With an enrolment of 78 pupils, it was the first Chinese institution of higher learning at that time in Southeast Asia, catering to Chinese dialect groups amongst the overseas Chinese. Six years later, the school moved to its Bukit Timah campus.

After its founding, the school offered comprehensive secondary level Chinese education. It remained funded and supported by Tan Kah Kee until shortly before World War II. In 1934, Lee Kong Chian, Tan Kah Kee's son-in-law, became the chairman of the school's board and remained in his post until 1955. During his tenure, the school faced the threat of closure several times due to financial difficulties, but managed to survive due to strong financial support from Lee and Tan. Together, they built a legacy which is currently commemorated by the school body through songs, plays, musical performances, and a heritage trail.

During the Battle of Singapore, the school's clock tower, due to its height, served as a vantage point and surveilance tower for both the Allied forces and Japanese army. Following the war, the school resumed its Chinese education. In the 1950s and 1960s, during periods of civil unrest in Singapore, many students, teachers and alumni participated in or led the anti-colonial riots.

After Singapore gained independence in 1965, the school came under the purview of the Ministry of Education and was accorded the Special Assistance Plan (SAP) status in 1979. Later, in 1988, the school achieved the status of an independent school. This scheme was perceived by the ministry as successful, and was thus extended to other well-performing schools in Singapore. On 19 March 1999, the school's clock tower was gazetted as a national monument.

In the late 1960s, Singapore's education system for secondary schools was in the form of a four-year programme followed by a two-year programme for pre-university education. The Chinese High School's board of directors decided to construct a junior college immediately adjacent to the school. This junior college was the second to be built in Singapore, and the first government-aided one.