- The Union Government and Asian Development Bank (ADB) on 7 May 2015 signed a 31 million US dollars loan agreement to boost water availability in selected river basins in Karnataka and ensure improved water efficiency in irrigation.
- The Union Cabinet on 6 May 2015 gave its approval for the revised Double Taxation Avoidance Agreement (DTAA) with South Korea.
- The Union Cabinet on 6 May 2015 gave its nod for allowing foreign investments into Real Estate Investment Trusts (REITs) by recognizing it as an eligible financial instrument or structure under the Foreign Exchange Management Act (FEMA) 1999.
- The Union Cabinet Committee on Economic Affairs (CCEA) on 6 May 2015 gave its nod for increase in the investment limit for cases requiring prior approval of Foreign Investment Promotion Board (FIPB) to 3000 crore rupees from the present 2000 crore rupees.
- Lok Sabha on 6 May 2015 passed the Goods and Services Tax (GST) Bill, 2014. The bill also called Constitution (122nd Amendment) Bill seeks to introduce GST regime in India.
- Book titled Unbelievable – Delhi to Islamabad authored by senior Advocate Prof. Bhim Singh was released on 8 May 2015 by Vice President M Hamid Ansari in New Delhi.
- Senior IPS officer Navneet Rajan Wasan was on 7 May 2015 appointed as (DG) of Bureau of Police Research and Development (BPR&D). He will serve the post till 30 November 2015, the date of his superannuation.
- Prime Minister Narendra Modi on 8 May 2015 released a commemorative coin to mark the birth centenary of Swami Chinmayananda in New Delhi.
- Mhairi Black on 7 May 2015 became the youngest lawmaker of Britain at the age of 20. The freshly elected lawmaker is from Scotland.
- Eminent historian and social scientist Amalendu Guha passed away on 7 May 2015 following old age ailments at Ulubari, Guwahati. He was 91.
- Nuclear Insurance Pool: A common insurance pool to pay for nuclear damages under the CLND Act, 2010.
- The French satirical magazine Charlie Hebdo was on 5 May 2015 presented with the 2015 Freedom of Expression Courage Award of the PEN American Centre at the American Museum of Natural History.
- World Asthma Day 2015 was observed globally on 5 May 2015. Theme of the year is You Can Control Your Asthma and sub-theme is It’s Time to Control Asthma.
- State Bank of India on 7 May 2015 launched State Bank RuPay Platinum debit card in association with National Payment Corporation of India (NPCI).
- Online fashion retailer Myntra.com on 6 May 2015 acquired Bengaluru-based startup firm Native5 Software Solutions Pvt Ltd for an undisclosed sum. With this acquisition, founders of Native 5 will join Flipkart, parent company of Myntra.
- Alibaba-backed company Paytm on 3 May 2015 tied-up with Quick service restaurants (QSRs) Domino’s and Cafe Coffee Day for offline payment. With this acquisition, Paytm's mobile wallet will soon be accepted at Domino’s and Cafe Coffee Day.
- Minerals and mining giant Vedanta Limited on 4 May 2015 launched its new logo. The logo was co-created by internal stakeholders across geographies and group companies.
- Maharashtra Food and Drug Administration (FDA) on 1 May 2015 ordered to file a FIR against the Snapdeal, its CEO Kunal Bahl and Directors for allegedly selling prescription drugs online. Selling of drugs without prescription is a crime under the Drugs and Cosmetics Act, 1940.
- Lok Sabha on 7 May 2015 gave its nod for the Repealing and Amending Bill, 2015 which seeks to repeal 36 archaic laws either partially or entirely as they have ceased to be in force or have become obsolete.
- Rajya Sabha on 6 May 2015 passed 119th Constitutional Amendment Bill on Land Boundary Bill (LBA).
- Lok Sabha on 7 May 2015 passed Juvenile Justice (Care and Protection of Children) Bill 2014. The Bill clearly defines and classifies offences as petty, serious and heinous, and defines differentiated processes for each category.
- Union Minister for Information & Broadcasting Arun Jaitley on 7 May 2015 launched the Mobile Application of DD News, E-version of India 2015 & Bharat 2015 and E-book of Ministry of Information and Broadcasting on its initiatives and achievements.
- North Korea on 8 May 2015 successfully test-fired a newly developed Submarine-Launched Ballistic Missile (SLBM). The nation described the missile as a world level strategic weapon.
- Indian and Russian institutions of higher learning on 8 May 2015 inked 11 Memorandum of Intent (MoI) to establish the Network of Institutions of Higher Education.
- David Cameron’s Conservative Party on 8 May 2015 won the UK General election 2015 by securing 331 seats in a Parliament of 650.
- Nepal Rastra Bank on 7 May 2015 announced to provide interest-free loans for rebuilding houses. The bank will provide interest-free loans of up to 25 lakh nepali rupees in the Kathmandu Valley and 15 lakh nepali rupees for those outside the capital for house reconstruction.
- The Indian Army team on 3 May 2015 emerged as champions in the 19th Federation Cup National Senior Athletic Championships. The team scored 123.5 points at the end of the four-day event at the Mangala Stadium in Mangaluru, Karnataka.
- American boxer Floyd Mayweather Jr. on 3 May 2015 defeated Manny Pacquiao from Philippines to win the unified World Welterweight title. The match termed as Fight of the Century was held at iconic MGM Grand, Las Vegas, Nevada.
- Switzerland tennis player Roger Federer on 3 May 2015 won the TEB BNP Paribas Istanbul Open Men’s singles title by defeating Pablo Cueves of Uruguay 6-3 7-6.
- A Special Genral Meeting (SGM) of the Boxing India (BI) on 3 May 2015 removed Sandeep Jajodia as its president.