Happy Birthday: William Boyd Watterson II (born July 5, 1958) is an American cartoonist who authored the comic strip Calvin and Hobbes. The strip was syndicated from 1985 to 1995. Watterson concluded Calvin and Hobbes with a short statement to newspaper readers that he felt he had achieved all he could in the medium. Watterson is known for his negative views on comic syndication and licensing, his efforts to expand and elevate the newspaper comic as an art form, and his move back into private life after Calvin and Hobbes ended. Watterson was born in Washington, D.C., and grew up in Chagrin Falls, Ohio. The suburban Midwestern United States setting of Ohio was part of the inspiration for the setting of Calvin and Hobbes. Watterson currently lives in Cleveland Heights, Ohio.

Watterson drew his first cartoon at age eight and spent much time in his childhood alone drawing and cartooning. This continued through his school years, during which time he discovered comic strips such as Walt Kelly's Pogo, George Herriman's Krazy Kat, and Charles M. Schulz's Peanuts which subsequently inspired and influenced his desire to become a professional cartoonist. On one occasion when he was in fourth grade, he wrote a letter to Schulz, who responded, much to Watterson's surprise. This made a big impression on him at the time. His parents encouraged him in his artistic pursuits. Later, they recalled him as a "conservative child" — imaginative, but "not in a fantasy way", and certainly nothing like the character of Calvin that he later created. Watterson found avenues for his cartooning talents throughout primary and secondary school, creating high school-themed super hero comics with his friends and contributing cartoons and art to the school newspaper and yearbook.

After high school, Watterson attended Kenyon College, where he majored in political science. He had already decided on a career in cartooning but he felt studying political science would help him move into editorial cartooning. He continued to develop his art skills and during his sophomore year he painted Michelangelo's Creation of Adam on the ceiling of his dormitory room. He also contributed cartoons to the college newspaper, some of which included the original "Spaceman Spiff" cartoons. Watterson graduated from Kenyon in 1980 with a Bachelor of Arts degree.

Later, when Watterson was creating names for the characters in his comic strip, he decided on Calvin (after the Protestant reformer John Calvin) and Hobbes (after the political philosopher Thomas Hobbes), allegedly as a "tip of the hat" to Kenyon's political science department. In The Complete Calvin and Hobbes, Watterson stated that Calvin was named for "a 16th-century theologian who believed in predestination" and Hobbes for "a 17th-century philosopher with a dim view of human nature".