The “Speak Mandarin Campaign”, launched in 1979, has become an on-going long-term annual event for 40 years. Over the years, the Campaign has gone through evolutionary changes in its target audience, annual objectives, and campaign strategies. As a long-lived language planning movement, the Campaign has made lasting impacts on the sociolinguistic profile, as well as the status of Mandarin vis-à-vis that of English and Chinese dialects in Singapore.