Katniss is the English common name of the edible aquatic plant Sagittaria — also called "arrowhead" or "duck-potato" — chosen by Suzanne Collins for her heroine to evoke wilderness, food gathering, and Diana the huntress. Katniss Everdeen of District 12 — protagonist of Suzanne Collins's The Hunger Games trilogy (2008-2010), the most popular American young adult dystopian series of the 21st century, with over 100 million copies sold. Portrayed by Jennifer Lawrence in the four-film adaptation (2012-2015) that grossed over $2.97 billion globally. The name has been steadily entering US baby-name records since 2012, peaking at around 150 births per year. A modern feminist warrior archetype.
Subject of Collins's The Hunger Games (2008), Catching Fire, and Mockingjay.
Katniss does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Katniss reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.