Prominent candidates in the first phase are Chief Minister Naveen Patnaik, and two former chief ministers and senior Congress leaders, Giridhar Gomang and Hemananda Biswal.
State Revenue Minister Surya Narayan Patro, former union minister and Bharatiya Janata Party leader Jual Oram, state BJP president K.V. Singh Deo, and Congress leader Narasingh Mishra are also in the fray.
Odisha saw intense campaigning by political heavyweights, including Congress president Sonia Gandhi, vice president Rahul Gandhi, BJP chief Rajnath Singh and prime ministerial candidate Narendra Modi.