 Social media platforms allow users to share news, ideas, thoughts and opinions on a global scale. Data processing methods allow researchers to automate the collection and interpretation of social media posts for efficient and valuable disease surveillance. Data derived from social media and internet search trends have been used successfully for monitoring and forecasting disease outbreaks such as Zika, Dengue, MEIS and Ebola viruses. More recently, data derived from social media have been used to monitor and model disease incidents during the coronavirus disease 2019, COVID-19 pandemic. We discuss the use of social media for disease surveillance. This article was authored by Avery E. Wilson, Christof Uliaman, Samay N. Saleh and others.