The actress will feature opposite Shah Rukh Khan in the Rohit Shetty production, Hindustan Times claims.
"Deepika is part of Chennai Express. She has been finalised," a source close to the project revealed.
A wide range of Bollywood actresses including Kareena Kapoor, Katrina Kaif and Priyanka Chopra had previously been linked to the project.
The film is expected to begin shooting in mid-September once Khan completes dubbing commitments on his current Yash Chopra-directed project.
Chennai Express explores what happens to Khan's character on board a long distance train journey from Mumbai to Rameshwaram.
Padukone made her debut opposite Khan in the 2007 blockbuster Om Shanti Om.