Blue's Clues is an American live-action/animated interactive educational children's television series, created by Angela C. Santomero, Todd Kessler, and Traci Paige Johnson, that premiered on Nickelodeon's Nick Jr. block on September 8, 1996, and concluded its run on August 6, 2006, with a total of six seasons and 143 episodes. The original host of the show was Steve Burns, who left in 2002 and was replaced by Donovan Patton (as "Joe") for the rest of the series. The show follows an animated blue-spotted dog named Blue as she leaves a trail of clues/paw prints for the host and the viewers to figure out her plans for the day.

The producers and creators combined concepts from child development and early-childhood education with innovative animation and production techniques that helped their viewers learn, using research conducted thirty years since the debut of Sesame Street in the U.S. Unlike earlier preschool shows, Blue's Clues presented material in a narrative format instead of a magazine format, used repetition to reinforce its curriculum, structured every episode the same way, and revolutionized the genre by inviting their viewers' involvement.

Research was part of the creative and decision-making process in the production of the show, and was integrated into all aspects and stages of the creative process. Blue's Clues was the first cutout animation series for preschoolers in the United States and resembles a storybook in its use of primary colors and its simple construction paper shapes of familiar objects with varied colors and textures. Its home-based setting is familiar to American children, but has a look unlike previous children's TV shows.

Upon debuting, Blue's Clues became the highest-rated show for preschoolers on American commercial television, and was critical to Nickelodeon's growth. It has been syndicated in 120 countries and translated into 15 languages. Regional versions of the show featuring local hosts have been produced in other countries. By 2002, Blue's Clues had received several awards for excellence in children's programming, educational software and licensing, and had been nominated for nine Emmy Awards.

A live production of Blue's Clues, which used many of the production innovations developed by the show's creators, toured the U.S. starting in 1999. As of 2002, over two million people had attended over 1,000 performances. A spin-off called Blue's Room premiered in 2004. A revival of the series titled Blue's Clues & You!, hosted by Josh Dela Cruz premiered on Nickelodeon on November 11, 2019. The show's extensive use of research in its development and production process inspired several research studies that have provided evidence for its effectiveness as a learning tool.