This article presents an overview of language policy in Hong Kong education during the colonial and post-colonial periods. The article is divided into three main sections. The first section outlines the sociolinguistic background of Hong Kong, including the demographic trends that have been crucial in determining the course of educational development in the city in the past 170 years. The second section offers an overview of language policies and practices during the colonial era (1842-1997). This section is divided into the two distinct phases which characterised education under the British; namely, (1) the period between the 1840s and the 1960s, during which English-medium secondary education was the preserve of the elite in society, and (2) the years between the 1970s and 1997, during which the majority of students in each age cohort attended schools in which English was the official medium of instruction. The third section examines developments in language policy since the handover, focusing on the promotion and subsequent fine-tuning of a controversial policy to promote Chinese-medium instruction at secondary level.[Copyright Liverpool University Press 2017]