Bachchan, who recently recreated the scene from "Sholay" for a TV show, made a collage of their photographs.
"Happy birthday to Dharam ji..," Bachchan tweeted.
In another tweet, the "Piku" star in reply to a fan's post wrote, "Wow .... Dharam ji... In his younger days... Still looks the same!!"
Touted as one of the most good looking actors of Bollywood, Dharmendra had once said he gets embarrassed when people compliment him.
Singer Shaan tweeted, "There have been many Handsome Heros... And then there is #Dharmendra! Happy Birthday Dharam Ji!!"
The Padma Bhushan awardee started off his career with romantic roles in films like "Bandini", "Dil Ne Phir Yaad Kiya" and "Phool Aur Paththar" before making a mark as an action hero in "Mera Gaon Mera Desh", "Satyakam", "Dharam Veer" and "Sholay".
Dharmendra's last release was "Yamla Pagla Deewana 2", which starred his sons Bobby and Sunny. He will reunite with his actor sons in "Ishq De Maare".