Tendulkar, who will turn 48 next month, retired from the professional game in 2013 after notching a still unmatched 100 international centuries in a prolific 24-year career.
He returned to the crease recently as captain of the India Legends team in a promotional event called the Road Safety World Series in Raipur, in the state of Chhattisgarh.
"I have been testing myself and taking all the recommended precautions to ensure COVID is kept at bay. However, I have tested positive today following mild symptoms," Tendulkar said on his Twitter handle.
"All others at home have tested negative. I have quarantined myself at home and I am following all the necessary protocols as advised by my doctors."
India on Saturday reported 62,258 new infections, its highest since October, taking its tally to 11.91 million. The death toll rose by 291 to stand at 161,240.
Tendulkar lives in Mumbai, the capital of the Western Indian state of Maharashtra which has been the hardest hit by a resurgence in cases.
Maharashtra has seen infections rising steadly and recorded an all-time high of 36,902 new cases on Friday with India's commercial capital Mumbai also reporting a high of 5,515 cases.
The state government has announced a night curfew from Sunday to stem the spread of the virus, while authorities could also impose local lockdowns in some districts after informing people in advance.