| 1 May | International Labour Day / May Day | Celebrates workers' rights; also Maharashtra Day & Gujarat Day (formed in 1960). |
| 2 May | World Tuna Day | Promotes sustainable fishing practices (UN-designated). |
| 3 May | World Press Freedom Day | Advocates for free media and journalist safety. |
| 4 May | Coal Miners Day / Intl. Firefighter's Day | Honors coal miners & firefighters for their sacrifices. |
| 4 May (First Sunday) | World Laughter Day | Promotes wellness through laughter (founded by Dr. Madan Kataria in 1998). |
| 6 May | International No Diet Day / World Asthma Day | Raises awareness on body positivity & asthma management. |
| 7 May | World Athletics Day | Encourages youth participation in sports (IAAF initiative). |
| 8 May | World Red Cross Day / World Thalassaemia Day | Marks Henry Dunant's birth & raises awareness on thalassemia. |
| 9 May | Rabindranath Tagore Jayanti / Maharana Pratap Jayanti | Celebrates Tagore's birth & Maharana Pratap's valor. |
| 10 May | World Lupus Day | Focuses on autoimmune disease Lupus. |
| 11 May | National Technology Day / Mother's Day | Commemorates Pokhran nuclear tests (1998); honors mothers. |
| 12 May | International Nurses Day / Buddha Purnima (Vesak) | Honors Florence Nightingale and celebrates Gautama Buddha's life. |
| 15 May | International Day of Families | Promotes policies supporting family structures. |
| 16 May | National Dengue Day / Intl. Day of Light | Raises awareness on dengue prevention & laser technology. |
| 17 May | World Telecommunication Day / Hypertension Day | Marks ITU's founding; encourages blood pressure awareness. |
| 18 May | World AIDS Vaccine Day / Intl. Museum Day | Supports HIV vaccine research; promotes museum heritage. |
| 20 May | International HR Day | Celebrates contributions of human resource professionals. |
| 21 May | National Anti-Terrorism Day / Intl. Tea Day | Observes Rajiv Gandhi's death; recognizes tea industry workers. |
| 22 May | Intl. Day for Biological Diversity | Highlights biodiversity conservation. |
| 23 May | World Turtle Day | Advocates for turtle protection. |
| 24 May | National Brother's Day | Celebrates sibling bonds. |
| 25 May | Africa Day | Marks African Union's founding (1963). |
| 26 May | National Memorial Day (USA) | Honors fallen US military personnel. |
| 30 May | Intl. Day of Potato / Goa Statehood Day | Recognizes potato's role in food security; Goa became state in 1987. |
| 31 May | World No Tobacco Day | WHO campaign against tobacco consumption. |
