"Honoured to serve India!" tweeted Modi after taking the oath.
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.
Former finance minister Arun Jaitley had written to Modi on Wednesday and said that he didn't want to be a part of the new government due to health reasons.
Top opposition leaders including former prime minister Manmohan Singh, Congress President Rahul Gandhi and UPA Chairperson Sonia Gandhi, corporate honchos, film stars, chief ministers and a galaxy of leaders from BIMSTEC countries were part of the nearly 8,000 guests at the ceremony.
Others who took oath of office as cabinet ministers are — Narendra Singh Tomar, Ravi Shankar Prasad, Harsimrat Kaur Badal, Thanwar Chand Gehlot, Ramesh Pokhriyal, Arjun Munda, Smriti Irani, Harsh Vardhan, Prakash Javadekar, Piyush Goyal, Dharmendra Pradhan, Mukhtar Abbas Naqvi, Prahlad Joshi, Mahendra nath pandey, Arvind Sawant, Giriraj Singh and Gajendra Shekhawat.
Those who took oath as minister of state with independent charge are — Santosh Kumar Gangwar, Rao Inderjit Singh, Shripad Yesso Naik, Jitendra Singh Kiren Rijiju, Prahalad Singh Patel, Raj Kumar Singh, Hardeep Singh Puri Mansukh L Mandaviya.
The ministers of state are — Faggan Singh Kulaste, Ashwini Kumar Choubey, Arjun Ram Meghwal, V K Singh, Krishan Pal, Danve Raosaheb Dadarao, G Kishan Reddy, Parshottam Rupala, Ramdas Athawale, Sadhvi Niranjan Jyoti, Babul Supriyo, Sanjeev Kumar Balyan, Dhotre Sanjay Shamrao, Anurag Singh Thakur, Angadi Suresh Channabasappa, Nityanand Rai, Rattan Lal Kataria, V Muraleedharan, Renuka Singh Saruta, Som Parkash, Rameswar Teli, Pratap Chandra Sarangi, Kailash Choudhary, Debasree Chaudhuri.
There are 24 cabinet ministers and as many MoS' while nine other were given MoS with independent charge rank.
Modi can have as many as 80 ministers in the 543-member Lok Sabha.
As per the Constitution, the total number of Union ministers, including the Prime Minister shall not exceed 15 per cent of the number of members in the LS.
This is the second time Modi took the oath at the forecourt of Rashtrapati Bhavan. Modi was sworn in by the then President Pranab Mukherjee in 2014 in the presence of over 3,500 guests including the heads of SAARC countries.
Earlier, Chandra Shekhar in 1990 and Atal Bihari Vajpayee in 1999 were sworn in at the sprawling forecourt.
Leaders of BIMSTEC countries including President of Bangladesh Abdul Hamid, Sri Lankan President Maithripala Sirisena, Nepal Prime Minister K P Sharma Oli, President of Myanmar U Win Myint and Bhutanese Prime Minister Lotay Tshering also attended the gala event.
From Thailand, its Special Envoy Grisada Boonrach represented the country. Besides India, BIMSTEC (Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation) comprises Bangladesh, Myanmar, Sri Lanka, Thailand, Nepal and Bhutan as members.
Kyrgyz President and current chair of Shanghai Cooperation Organisation Kyrgyz President Sooronbay Jeenbekov, and Mauritius PM Pravind Kumar Jugnauth also attended the event.
Mukesh Ambani, Ratan Tata, steel baron L N Mittal and Adani Group head Gautam Adani were among the who's who of corporate India present.
RBI Governor Shaktikanta Das, Essar Director Prashant Ruia, Tata Group Chairman N Chandrasekaran, Vedanta Chairman Anil Aggarwal and HDFC's Deepak Parekh were there as well.
Making a starry splash were showbiz stars, including those who were voted into power like Hema Malini and her stepson Sunny Deol. Others like cine star Rajinikanth, filmmaker Karan Johar, Shahid Kapoor, Boney Kapoor and Kangana Ranaut added a touch of glamour. Sidharth Roy Kapur, president of the Film and Television Producers Guild of India, Vivek Oberoi, Anupam Kher, Madhur Bhandarkar and Boney Kapoor were also a part of the event.
"The kind of victory they have had, it is almost like a celebration. It is celebration of democracy," Boney said.
It was an eclectic gathering. Among those invited were the families of the BJP workers allegedly killed during political violence West Bengal as well as those of one of the martyrs of the Pulwama terror attack.