Pebbles is a brand of breakfast cereal which was introduced in the United States by Post Consumer Brands on October 20, 1971 featuring characters from the animated series The Flintstones as spokestoons. The product line includes Cocoa Pebbles and Fruity Pebbles.

Cocoa Pebbles contains chocolate-flavored crisp rice cereal bits, while Fruity Pebbles contains crisp rice cereal bits that come in a variety of fruit flavors with a sugar content of 9 grams per serving for Fruity Pebbles and 10 grams per serving for Cocoa Pebbles. It is the oldest cereal brand based on characters from a TV series or movie that is still sold.

Fruity Pebbles and Cocoa Pebbles Cereal were reintroductions of a low market-share Post children's cereal brand called Sugar Rice Krinkles. The Product Group Manager at the time, Larry Weiss, licensed use of The Flintstones for cereal from Hanna-Barbera Productions (now part of Warner Bros. Animation) in an attempt to reinvigorate the children's cereal business for Post Cereals. Prior to that time, character licensing had been used for promotion, but there had never been a brand created around a media character. The brand was marketed despite internal concern it would be a fad and not last more than a year. Fruity Pebbles was introduced on the West Coast in 1969 first under simply the name "Pebbles" and strong consumer demand led to national distribution under the cereal rename of "Fruity Pebbles". In 1970, Cocoa Pebbles was introduced as a second flavor. The brand has been one of the most consistent best sellers ever since.

The original working names for the companion cereals were Flint Chips and Rubble Stones, consistent with the appearance of the cereal and The Flintstones' Stone Age imagery. Frank Corey, Benton & Bowles' creative head for the Post Cereal business, suggested the alternative names Cocoa Pebbles and Fruity Pebbles, which were adopted.

The basic product retained the Sugar Rice Krinkles form, using the existing expander process and Battle Creek production facilities. After many iterations, the Cocoa Pebbles formula was set and has remained largely unchanged over the years. Fruity Pebbles also remained essentially unchanged for decades. In recent years, some additions, and variations have been made to the Fruity Pebbles product formulation. The Canadian version, no longer available, came in the form of pebble-shaped puffs composed of whole wheat, cornflour, and oat flour. Both Fruity Pebbles and Cocoa Pebbles were reformulated in the early-2010s industry-led sugar reduction effort: the original formulation contained 12 grams per 3/4 cup serving, while the 2011 reformulation (still current as of 2024) contains 9 grams sugar per 3/4 cup serving.

Unlike its sister cereal Cocoa Pebbles, Fruity Pebbles has undergone many formula changes, additions and variants. The cereal started out with three colors—orange, red, and yellow—and natural orange, lemon, and tangerine flavors, but were later flavored in natural orange and artificial lemon and cherry. New colors were added over time: purple in 1985, green in 1987, "Berry Blue" in 1994, "Incrediberry Purple" in 1995, and "Bedrock Berry Pink" in 2005.

Upon Post's acquisition of MOM Brands in 2015 (the former Malt-O-Meal), both the Cocoa and Fruity versions of Pebbles, along with other Post brands, began to be offered in packaging similar to that of Malt-O-Meal's discounted generic line of bagged cereals alongside the traditional box sizes.

Pebbles has since expanded beyond only producing cereal. To celebrate the products' 50th birthday in 2021, Post partnered with the Love Your Melon hat company to produce winter hats and shirts. Post has also licensed other food companies to put out other food products that bear both the Fruity and Cocoa Pebbles flavors including protein powder, white chocolate bars (with the actual cereal mixed in), ice cream (with or without the actual cereal in it), crisps, and Fruity and Cocoa Pebbles Marshmallow Treats (like those made with Rice Krispies), among others.^{[citation needed]}