"Dear Amitji wish u a happy 70th birthday. May God bless u with happiness and good health," Tendulkar wrote on his Facebook page.
The post, which has a photo of Tendulkar and Bachchan got 31,934 likes and 1,866 comments within three hours.
The two of the most recognisable public faces in the country, Tendulkar and Bachchan have shown mutual admiration for each other in the past.
Bachchan has been a regular in appreciating the cricketing feats of Tendulkar in social media sites and other fora.
"India breathes normally. Sachin completes an incredible feat. A hundred 100's .. Never done before, perhaps never after," Bachchan had written on his Twitter page earlier this year after Tendulkar scored his 100th international century in Bangladesh.