Torquay are the first club in the top five leagues to sack their manager this season, with Kevin Nicholson leaving his post 12 days into the campaign.
The 36-year-old, who had acted as the club's player-manager since September 2015, made close to 400 appearances for the National League side as a full-back.
He helped United avoid relegation in his first season but continued success was hard to find and Torquay were just three points clear of the drop zone at the end of last season.
This term, Torquay are bottom of the National League with one point from 12 and Nicholson said he was "embarrassed" by Tuesday's 4-2 loss to Boreham Wood.
"Torquay United Football Club have announced the departure of player-manager Kevin Nicholson with immediate effect," a statement read.
"As a football club, we would like to thank Kevin for all his hard work as a manager and player for Torquay United, and we wish him well for the future."
