- May 1 Creagen Dow, American actor (Zoey 101), born in Lake Wales, Florida
- May 1 Marcus Stroman, American MLB baseball pitcher (All-Star, 2019; Gold Glove, 2017; Toronto Blue Jays, NY Mets), born in Medford, New York
- May 3 Carlo Acutis, English-born Italian Catholic website designer and the 1st millennial saint, born in London (d. 2006) [1]
- May 3 Samuel Seo, South Korean R&B singer-songwriter, rapper, and record producer ("Kafka"), born in Seoul, South Korea
- May 9 Majlinda Kelmendi, Kosovar-Albanian judoka (Olympic gold 2016), born in Peć, SFR Yugoslavia
- May 10 Emily McEnroe, daughter of Tatum O'Neal & John McEnroe
- May 10 Kenny Beats [Blume], American hip-hop record producer and songwriter, born in Greenwich, Connecticut
- May 19 Jordan Pruitt, American singer (The Voice), born in Loganville, Georgia
- May 19 Moses Sumney, American singer-songwriter (Græ), born in San Bernadino, California
- May 21 Kayla Itsines, Australian fitness entrepreneur (Bikini Body Guides), born in Adelaide, Australia
- May 21 Sarah Ramos, American actress (Parenthood), born in Los Angeles, California
- May 23 Aaron Donald, American NFL football defensive end, Defensive Rookie of the Year, 7x Pro Bowls, 3x Defensive Player of the Year (St. Louis/Los Angeles Rams), born in Pittsburgh, Pennsylvania
- May 23 Sarah Jarosz, American singer-songwriter (World on the Ground), born in Austin, Texas
- May 24 Erika Umeda, Japanese singer (ZYX), born in Minami-ku, Yokohama, Japan
- May 27 Beauden Barrett, New Zealand rugby union utility back (83 caps; World Male Rugby Player of the Year 2016, 17; Hurricanes 125 games), born in New Plymouth, New Zealand
- May 28 Alexandre Lacazette, French soccer player, born in Lyon, France
- May 29 Kristen Alderson, American actress (One Life to Live), born in Huntington Valley, Pennsylvania
- May 31 Azealia Banks, American rapper (212), born in New York City
About May 1991
How Old? 33 years old
Generation: Millennial
Leap Year: No
Chinese Zodiac: Goat/Sheep
Star Signs: Taurus (Apr 20 - May 20), Gemini (May 21 - Jun 20)
20-29
30-39
40-49
50-59
80-89
Over 90