"Kushboo will join our party in the presence of party chief Sonia Gandhi in New Delhi," Tamil Nadu Congress President E V K S Elangovan told PTI from Delhi.
Congress leaders feel that the entry of the popular actress would be a morale booster at a time when senior leader G K Vasan had deserted it with his followers.
Known for her penchant for making controversial remarks like the one on pre-martial sex, Kushboo quit the DMK on June 16, saying she was slighted by the party leadership.
In a letter to DMK chief M Karunanidhi, she had complained that her hardwork had become a one-way path in the party.
She joined the DMK in May, 2010 when it was the ruling party in Tamil Nadu.
Kushboo's house had come under attack last year after she made certain comments about leadership succession in the DMK, which attracted the wrath of supporters of party Treasurer M K Stalin.