Telford, capped 27 times by the Lionesses, won three Women's Super League titles with the Blues.
She went to Euro 2017 as a squad member, and played at the 2019 World Cup, also going to the Tokyo Olympics with Great Britain in 2021.
"After 20 years playing the beautiful game, it's time for me to hang up the old boots and gloves," Telford posted on social media.
