Claire Wright, who has represented Otter Valley since 2013 is standing down after winning the largest majority of any county councillor two terms running.
She was also an independent parliamentary candidate for East Devon in 2015 and 2017, when she won a 25% vote share.
However, despite increasing her vote share to over 40% the national swing preserved 150 years of continuous Conservative East Devon representation at Westminster.
She was previously a councillor on East Devon District Council from 2011 to 2015 and Ottery St Mary Town Council from 2009 to 2013.
She said: “My decision to stand aside may come as a surprise to people.
“However, I have quietly been considering my position for some time and although it has been an honour and privilege to serve my community in this way, it is now time to step aside to pursue other career opportunities.”