Shaw, 35, took charge last summer and led the Holy Blues to 16th in the NPL Premier Division, though they boated one of the best home records in the division, losing just twice at home all season.
A club statement said: “Gainsborough Trinity Football Club can confirm that Tom Shaw has today left his position as first team head coach with immediate effect.
“The club will be making no further comments at this time.”
Shaw combined his role at Gainsborough with a job at Lincoln City, where he finished his playing career in 2018.
Keep up-to-date with our exclusive email newsletters.
Subscribe