The mathematical foundation of Sudoku dates back to the 18th century when Swiss mathematician Leonhard Euler developed the concept of Latin squares. These were arrangements where each symbol appears exactly once in each row and column. While not identical to modern Sudoku, Latin squares established the logical principles that would later define the puzzle.

The puzzle we recognize today as Sudoku was invented in 1979 by American architect Howard Garns and published in Dell Magazines under the name "Number Place." Garns created a 9×9 grid puzzle with the additional constraint of 3×3 regions, adding a new layer of complexity to the traditional Latin square concept.

In 1984, the puzzle was introduced to Japan by Maki Kaji, president of the Japanese puzzle company Nikoli. He gave it the name "Sudoku," which is short for "Sūji wa dokushin ni kagiru," meaning "the digits must be single" or "the digits are limited to one occurrence." The puzzle quickly became a cultural phenomenon in Japan, where logic puzzles have a strong tradition.

Sudoku remained primarily a Japanese phenomenon until 2004, when Wayne Gould, a retired Hong Kong judge and puzzle enthusiast, developed a computer program to generate Sudoku puzzles. He convinced The Times of London to publish them, and the puzzle rapidly spread to other newspapers worldwide. By 2005, Sudoku had become an international sensation, appearing in newspapers across Europe, America, and beyond.

The rise of smartphones and tablets in the 2010s brought Sudoku to a new generation of players. Digital versions offered features impossible in print: automatic error checking, hints, multiple difficulty levels, and the ability to play anywhere. Today, Sudoku apps have been downloaded hundreds of millions of times, making it one of the most popular puzzle games in the world.

As Sudoku's popularity grew, competitive solving emerged. The first World Sudoku Championship was held in Lucca, Italy, in 2006. Today, international competitions attract the world's fastest solvers, with champions completing expert-level puzzles in under five minutes. The World Puzzle Federation now organizes annual championships, and Sudoku has become a recognized mind sport.

The success of classic Sudoku has inspired countless variations: Killer Sudoku (with arithmetic clues), Samurai Sudoku (five overlapping grids), Irregular Sudoku (non-square regions), and many more. These variants keep the core logic while adding new challenges, ensuring the puzzle remains fresh and engaging for dedicated solvers.

Beyond entertainment, Sudoku has been studied for its cognitive benefits. Research suggests regular puzzle-solving may help maintain mental acuity and could be beneficial for brain health. The puzzle has been used in educational settings to teach logical thinking and problem-solving skills. Its universal appeal transcends language and culture, making it a truly global phenomenon.