Also in contest that day are AAP leader Arvind Kejriwal, one of two main opponents of Modi in Varanasi, and Samajwadi Party chieftain Mulayam Singh Yadav, who is fighting it out in Azamgarh. The Monday voting will mark the end of staggered polling in Uttar Pradesh, a politically critical state that picks 80 Lok Sabha MPs, as well as the entire country.
Keeping in mind the high stakes, the Election Commission has declared 13 of the 18 seats as "highly sensitive" -- official euphemism to mean they are prone to violence.
Over 30 million people will be eligible to vote in over 31,000 polling stations Monday.
The one constituency that has attracted most attention in this election is Varanasi -- because of Modi's candidature. Also pitted against Modi in the Hindu holy city is Ajay Rai of the Congress.
Mulayam Singh Yadav's main opponent is the Bharatiya Janata Party's Ramakant Yadav, the incumbent MP. It is the second Lok Sabha seat Yadav is contesting in the state.
Broadly called the Poorvanchal, the region where balloting will be held Monday borders Bihar on one side and Nepal on the other.
In the outgoing Lok Sabha, the Samajwadi Party had six members from this region, the Bahujan Samaj Party (BSP) five, the BJP four and the Congress three members.
A resurgent BJP led by Modi is trying to wrest as many seats as possible from the other parties.
The BJP, which in 2009 won from Bansgaon, Azamgarh, Varanasi and Gorakhpur, is determined to do well seemingly in the reckoning in the Kushi Nagar, Domariyaganj and Deoria constituencies too.
The BJP has never won any election in Ghosi, Ballia, Lalganj and Salempur, considered a socialist bastion. The BJP is determined to spread its wings in these places.
In Gorakhpur, like always, the political discourse revolves around Mahant Adityanath, the outgoing BJP MP known for his aggressive promotion of Hinduism.
With Muslims steadfastly behind it in 2009, the Congress lapped up three seats in the region.
One of its winners then, Jagdambika Pal (Domariyaganj), has this time hitched the BJP bandwagon and is seeking re-election.
Mukhtar Ansari, who withdrew from the fray in Varanasi despite coming a close second to the BJP in 2009, is now the Quami Ekta Dal candidate in nearby Ghosi. In Varanasi, he has announced support for the Congress.
The BJP is eying the sizeable Brahmin and Thakur vote in Ghosi to checkmate Ansari. The BJP is equally confident in Lalganj where it had lost in 2009 narrowly.
The widely recognized front-runner in Kushi Nagar is Minister of State for Home Affairs R.P.N. Singh of the Congress.
Chandauli, Mirzapur, Machhlishahr, Jaunpur, Lalganj and Bansgaon will see triangular contests involving the BJP, the BSP and the Samajwadi Party.
With a high-octane campaign thus far, political pundits believe the polling for 18 seats from Uttar Pradesh Monday will be crucial to all key players in the sprawling state.