"Congratulations to Shri M K Stalin on being elected President of the DMK. I wish him happiness & success as he begins a new chapter in his political journey. @mkstalin #DMKThalaivarStalin," Rahul wrote wrote on the micro-blogging site Twitter.
Mamata also took to Twitter to congratulate Stalin.
"Congratulations and best wishes to @mkstalin for being elected President of the DMK @arivalayam," the TMC chief tweeted.
MDMK founder Vaiko also wished Stalin many successes in his new post and a long life.
Stalin was on Tuesday elevated as the DMK president at the party's General Council meeting held in Chennai. This makes him the second leader after his late father M Karunanidhi to be elected to post of DMK president after 50 years.
Stalin was elected unopposed, as he was the sole candidate who had filed nomination for the party chief's post on August 26, DMK General Secretary K Anbazhagan said at the DMK council meeting.