- Asian Pacific American Heritage Month- Recognizes the contributions and celebrates the culture of Asians and Pacific Islanders in the United States.
- Jewish American Heritage Month – Recognizes the history of Jewish contributions to American culture, acknowledging the diverse achievements of American Jews.
- Older Americans Month
- National Photography Month
- National Salad & Salsa Month
- Mental Health Awareness Month
- National Blood Pressure Education Month
- Nurses Week—May 6-12
- Teacher Appreciation Day- May 6
- May 1 – International Worker’s Day – Also known as May Day, it celebrates the social and economic achievements of workers worldwide. The day commemorates the Haymarket Riot of 1886 in Chicago, in which police and protesters clashed following a workers’ strike for an eight-hour work day.
- May 3 – World Press Freedom Day – Serves as an occasion to inform the public of violations of the right to freedom of expression and as a reminder that many journalists brave death or jail to bring people their daily news.
- May 5 – Cinco De Mayo – In 1862 Mexican forces defeated French occupational forces in the Battle of Puebla.
- May 15-16 – Lag B’omer – Jewish Celebrates the end of a divine-sent plague and/or Roman occupation during Rabbi Akiva’s lifetime (died c. 135 CE).
- May 11 – Mother’s Day – Children of all ages show appreciation for their mothers and mother figures.
- May 21 – Employee Health & Fitness Day – this day aims to promote the importance of employee health and fitness, encouraging individuals to engage in physical activity, make healthy lifestyle choices and prioritize well-being.
- May 16 – Malcolm X Day – Civil rights leader, founder of Organization of Afro-American Unity. It is celebrated on May 19, his birthday, or the third Friday of May. He is celebrated because of his civil rights leadership during the civil rights movement from 1954 to 1965.
- May 21 – World Day For Cultural Diversity – Recognizes cultural diversity as a source of innovation, exchange and creativity, as well as the obligation to create a more peaceful and equitable society based on mutual respect.
- May 22-23 – Declaration Of The Báb – Bahá’í Commemoration of May 23, 1844, when the Báb, the prophet-herald of the Bahá’í Faith, announced in Shíráz, Persia, that he was the herald of a new messenger of God.
- May 25 – Ascension Day – Western Christian. Celebrated 40 days after Easter/Pascha, it commemorates the ascension of Jesus into Heaven.
- May 29- Ascension Day – Eastern Orthodox Christian- Also known as Holy Ascension, celebrated 40 days after Pascha, it commemorates the ascension of Jesus Christ into Heaven.
- May 12 – Visakha Puja – Buddhist Also known as Vesak or Buddha Day, it marks the birth, spiritual awakening, and death (nirvana) of the historical Buddha.
- May 27-28 – Ascension Of Bahá’u’lláh – Bahá’í Observance of the anniversary of the death in exile of Bahá’u’lláh, the prophet-founder of the Bahá’í Faith.
- May 26 – Memorial Day – A federal holiday in the United States for remembering the people who died while serving in the country’s armed forces.
