Kumar chose not to celebrate this year as a mark of respect to prominent personalities from the film fraternity and Shiv Sena supremo Bal Thackeray, who passed away in recent months.
Several from Bollywood and others greeted Kumar, describing him as the "undisputed king" of Indian cinema.
Megastar Amitabh Bachchan tweeted, "90 years of the legend Dilip Kumar, Yusuf Saheb, today... Never before never after!! History of Indian actors shall be written - 'before Dilip saheb, after Dilip saheb'... Spent wonderful evening with him recently!!"
Anupam Kher posted, "For me Dilip Saab will always be undisputed KING of 100 years of Indian Cinema. Happy Birthday Sir."
Actress Shabana Azmi called him an inspiration: "Happy birthday Dilip Saheb. There has not been another like you. We continue to draw inspiration from your performances and your commitment."
"In my dictionary Dilip Kumar means dignity, depth, sensitivity, subtlety, sophistication and class. Happy birthday Dilip saheb," said Javed Akhtar.
Pakistani singer-actor Ali Zafar posted, "My favourite actor Dilip Kumar turns 90 today. What a day!"
"Salute to Dilip sahab and his commitment to the craft! May you live for 1000 years and keep entertaining us!," actor Manoj Bajpayee tweeted.
"The reference point for almost every thinking actor, Dilip Kumar turns 90 today! We are fortunate that we live in the same time as he does!!," said actor Nikhil Dwivedi.
Information and Broadcasting minister Manish Tewari also conveyed his best wishes to the legend on his birthday.
