She was administered the oath of office and secrecy by Governor Surjit Singh Barnala at the University Centenary Hall. Jayalalithaa will head a 34-member government in the 14th Tamil Nadu assembly.
Barnala also administered oath of office to the council of ministers, days after the AIADMK-led alliance dealt a crushing blow to the DMK-led alliance led by veteran M. Karunanidhi.
Senior politicians like Gujarat Chief Minister Narendra Modi and former Andhra Pradesh chief minister N. Chandrababu Naidu as well as Tamil film personalities were present at the event.
The swearing-in ceremony was also attended by Communist Party of India (CPI) leader A.B. Bardhan, DMDK leaders A. Vijayakanth and Panrutti S. Ramachandran, SMK leader R. Sarathkumar and his wife Radhika.
Chief Justice of Madras High Court M.Y. Eqbal, other judges and members of the Bar Council were also present.
All those who were present at the hall, including Jayalalithaa, had a hearty laugh when C. Karuppasamy took oath in a loud rhythmic staccato voice as the minister for animal husbandry.
Political commentator Cho Ramaswamy was seen gesticulating his hands in sync with Karuppasamy's oath.
A large number of people gathered at the venue. People lined up on both sides of the road, starting from Jayalalithaa's residence at Poes Garden and along the entire stretch of Kamaraj Salai on the Marina till the Madras University campus.
Two giant screens were installed outside the venue so that people could view the swearing-in ceremony.
Leaders of rival camp - DMK, Congress and PMK- stayed away from the swearing-in ceremony.
The AIADMK-led front won 203 seats in the 234-member Tamil Nadu assembly. The AIADMK won 150 seats - 146 on its own and four by allies who fought under its election symbol.