Modi, 68, was administered the oath of office and secrecy by President Ram Nath Kovind at a glittering ceremony at the forecourt of majestic Rashtraparti Bhavan.
Apart from Shah, Singh, Gadkari, the other top leaders who were sworn-in as cabinet ministers included D V Sadananda Gowda, Nirmala Sitharaman and Ram Vilas Paswan.
While the inclusion of Shah, seen as BJP's key strategist who helped the party to expand its base after taking over the reins of the party in 2014, was much speculated, Jaishankar, considered close to Modi, was a surprise pick.
Some of the key ministers in the previous Modi government, including Sushma Swaraj, Rajyavardhan Singh Rathore and Maneka Gandhi were not part of the new council of ministers.
Here's a region-wsie breakup of the new Modi cabinet
Uttar Pradesh (9): Narendra Modi, Rajnath Singh, Smriti Irani, Mahendra Nath Pandey, Santosh Gangwar, Hardeep Singh Puri, VK Singh, Sadhvi Niranjan Jyoti and Sanjeev Balyan
Bihar (6): Ram Vilas Paswan, Ravi Shankar Prasad, Giriraj Singh, RK Singh, Ashwini Chaubey, Nityanand Rai
Maharashtra (8): Nitin Gadkari, Prakash Javadekar, Piyush Goyal, Arvind Sawant, Raosaheb Danve, Sanjay Dhotre, Ramdas Athawale and V Muraleedharan.
Madhya Pradesh (5): Narendra Singh Tomar, Thawar Chand Gehlot, Dharmendra Pradhan, Faggan Singh Kulaste and Prahlad Patel.
Rajasthan (3): Gajendra Shekhawat, Arjun Meghawal and Kailash Chaudhary
Gujarat (3): Amit Shah, Purushottam Rupala and Mansukh Mandawiya
Chhattisgarh (1): Renuka Singh Saruta
Delhi (1): Harsh Vardhan
Haryana (3): Roa Indrajeet Singh, Krishan Pal Gurjar and Rattan Lal Kataria
Punjab (2): Harsimrat Kaur Badal and Som Prakash
Uttarakhand (1): Ramesh Pokhariyal Nishank
Jharkhand (2): Arjun Munda, Mukhtar Abbas Naqvi
Karnataka: (4) Sadananda Gowda, Nirmala Sitharaman, Pralhad Joshi and Suresh Angadi
West Bengal (2): Babul Supriyo and Debasree Chaudhuri
Jammu and Kashmir (1): Jitendra Singh
Telangana (1): G Kishan Reddy
Goa (1): Shripad Naik
Odisha (1): Pratap Chandra Sarangi
Assam (1): Rameshwar Teli
Arunachal Pradesh (1): Kiren Rijiju
Himachal Pradesh (1): Anurag Thakur