The actor, whose recently released film '2 States' has created magic at the Box Office , joined micro-blogging site Twitter two days ahead of his birthday.
On the occasion of his special day, Arjun tweeted: "Thank you each and everyone of you...@monakapoor3 love u mom..hope u smiling ur son is 29 now..time to pretend to be mature...."
Arjun made his acting debut with Habib Faisal's romantic drama 'Ishaqzaade' in 2012.
He then portrayed dual roles in Atul Sabharwal's crime thriller Aurangzeb in 2013.
The year 2014 proved to be quite lucky for the actor as he starred in two commercially successful films-'Gunday' and '2 States'.
Both films earned positive reviews for his performances in them.
As the actor turned 29, his upcoming film 'Finding Fanny', which in an English and Konkani satirical, will soon hit the theatres.