The actress, who tied the knot with the "Sholay" star in 1979, recalled the lovely moments the two have spent together.
"Recalling today the best years of my career, best & happy years of togetherness till date and the two lovely babies we have. Happy Birthday Dharamji!," Malini wrote.
The duo starred together in many films including "Raja Jani," "Seeta Aur Geeta," "Sharafat," "Naya Zamana," "Patthar Aur Payal," "Tum Haseen Main Jawaan," "Jugnu," "Dost," and "Charas".
The couple have two daughters Esha and Ahana. Esha also wished her father on the special day.
Born in 1935 in Nusrali, a village in Ludhiana district, Punjab, Dharmendra made his acting debut with 1960 film "Dil Bhi Tera Hum Bhi Tere".
He went on to star in films like "Bandini", "Phool Aur Paththar", "Anupama", "Chupke Chupke" and "Sholay" which went on to become his biggest hit.