Warhammer 40,000 and Age of Sigma is a miniature wargame produced by Games Workshop. It is the most popular miniature wargame in the world. It is most popular in Britain. The first edition of the rulebook was published in September 1987, and the eighth edition was published in June 2017. The ninth edition will be released in 2020.

As in other miniature wargames, players enact a battle using miniature models of warriors and fighting vehicles. The playing area is a tabletop model of a battlefield, comprising models of buildings, hills, trees, and other terrain features. Players take turns to move their model warriors around the battlefield and pretend that they are fighting the other player's warriors. These imaginary fights are resolved using dice and simple arithmetic.

Warhammer 40,000 is set in the distant future, where a stagnant human civilisation is beset by hostile aliens and malevolent supernatural creatures. The models in the game are a mixture of humans, aliens, and supernatural monsters, wielding futuristic weaponry and magical powers.

 Age of Sigmar has a fantasy theme heavily inspired by the fiction of J.R.R Tolkien and Michael Moorcock. Player's armies fight with medieval-era weaponry and cast magical spells, and the warriors are a mixture of humans and fantasy creatures such as elves, dwarves, and orks