Welcome to the 2017 Special Issue on the IEEE Circuits and Systems Society (CASS) Regional Flagship Conferences, a collection of selected papers presented at the 2016 IEEE Asia Pacific Conference on Circuits and Systems (APCCAS 2016), held in Jeju, South Korea, October 25–28, 2016, the 23rd IEEE International Conference on Electronics Circuits and Systems (ICECS 2016), held in Monte Carlo, Monaco, December 11–14, 2016, and the 8th IEEE Latin American Symposium on Circuits and Systems (LASCAS 2017), held in Bariloche, Argentina, February 20–23, 2017. In APCCAS 2016, 212 papers were presented, selected from 310 papers submitted; in ICECS 2016, 191 papers were presented, selected from 353 papers submitted; in LASCAS 2017, 70 papers were presented, selected from 172 papers submitted.