VK Sasikala's nephew and the AIADMK Deputy General Secretary TTV Dinakaran was nominated as the party's candidate for the RK Nagar bypoll scheduled for 12 April.
The official announcement was made by the party presidium chairman K.A. Sengottaiyan on Wednesday.
Addressing media after the announcement, Dinakaran said he is confident that he would win the seat with a margin of over 50,000 votes.
The AIADMK leader would contest under the party's 'Two Leaves' symbol in the seat that was declared vacant following the death of former Chief Minister Jayalalithaa.
Our opponent is only the DMK and not any other party or individual and the party was open to receiving support from anyoneTTV Dinakaran, AIADMK Deputy General Secretary
The rebel faction led by former CM O Panneerselvam has approached the Election Commission claiming that the 'Two Leaves' symbol belongs to the
According to AIADMK statement, the decision to field Dinakaran was taken at the party parliamentary board meeting.
Dinakaran, nephew of Sasikala, is a former MP.
This will be the first election which the AIADMK will face post Jayalalithaa's death.
While AIADMK will seek to continue its electoral dominance, the 12 April by-election is seen as an indicator of the people's mindset in the wake of Jayalalithaa's demise and the rift in the ruling party.
Dinakaran, who was expelled from the AIADMK in 2011, was re-inducted into the party last month by Sasikala after he expressed regret for his alleged anti-party activities.
Subsequently, he was appointed as the party's Deputy General Secretary making him the second-in-command after Sasikala, who is now serving a jail term in Bengaluru, in connection with the Rs 66 crore disproportionate assets case.
Sasikala, her husband M Natarajan and close relatives Dinakaran and Venkatesh were expelled from the AIADMK in 2011 by Jayalalithaa amidst reports then that they interfered in party and government administration.