Total Annihilation is a science fiction real-time strategy video game released in September 1997 for Microsoft Windows and Mac OS by Cavedog Entertainment and distributed internationally by GT Interactive. Two expansion packs were released in 1998, The Core Contingency on April 29 and Battle Tactics on July 20, while a medieval-themed spin-off called Total Annihilation: Kingdoms was released on June 25, 1999.

Rights to the game passed to Infogrames (later Atari) following the 1999 acquisition and closure of Cavedog Entertainment's parent company, Humongous Entertainment. In July 2013, Wargaming bought the Total Annihilation franchise from Atari's bankruptcy proceedings.

Total Annihilation has been re-released on Steam and GOG, but is no longer actively supported. The creators of XTA, a mod for Total Annihilation, independently developed the open-source 3D graphics Spring game engine. The Total Annihilation 3D project began in 2006. Former lead designer Chris Taylor went on to found Gas Powered Games which created Supreme Commander in 2007, considered the "spiritual successor" of Total Annihilation.

Total Annihilation is set in the far future in the midst of a galactic war, with battles taking place on the surface of planets and moons. The efforts of the player are centered on constructing a defensive base and an offensive force, and conquering opponents. The player is also concerned with gathering resources, reconnaissance and stealth, and evaluation of units and terrain. Battles take place against AI in a story-driven campaign, with the option of playing against other players in a skirmish mode.

When starting a new game, the player normally begins with a lone Commander. The Commander is a powerful and irreplaceable unit that has a number of unique abilities such as a destructor weapon that vaporizes anything it hits, the ability to use cloaking and become invisible, and the ability to travel through bodies of water. Construction is governed by the possession of the game's two unlimited resources, Metal and Energy, and can be undertaken by factories or mobile construction units. Every unit belongs to a level of technology (tech level); the higher the level, the more advanced the unit and the more resources and thus time required to construct it. A feature of the game is the ability to easily "queue" the many commands for a unit or group of units, with types of commands including patrolling a route, constructing a defensive group of structures and attacking enemy units. Once given its commands, the unit will go about them automatically thus minimizing the need for the player's attention to small, repetitive tasks. The victory conditions of a multiplayer game generally involve the elimination of all enemy units, but the aim of single player campaign missions can be more specialized.

Resources in Total Annihilation are handled in a manner different from other real-time strategy games of the day: they are "streaming", meaning that they are accumulated at a constant rate rather than in small batches; and they are limitless. In addition, all units and structures have a fixed cost, but they build at varying rates depending on the unit constructing them. A Commander, for example, will build a structure three times faster than a construction vehicle, but at a higher cost in energy. If the rate at which resources are used exceeds the rate at which resources are acquired, then the player's reserves will begin to be depleted. If a player's reserves are entirely depleted, the player's production across the board will slow to a rate proportional to the amount by which outflow exceeds income, this is known as "nanostalling". In addition, if the player runs out of energy, power-dependent structures such as radar towers, metal extractors, and laser towers will cease to function. This adds an element of economic complexity unparalleled in most RTS games of the time period. When a unit or structure is destroyed, it leaves behind wreckage that may be reclaimed for a lump sum of metal. Many terrain structures may also be reclaimed for their metal. Some maps also have plants or other organic structures that can be reclaimed for energy.

The player can command a variety of units including infantry bots, vehicles, ships, hovercraft, aircraft, powerful stationary long range weapons, and even a giant mecha known as the Core Krogoth. Units vary in size, speed and the ability to give and take damage, depending on their tech level. The strongest units take longer to build as well as cost more resources. Each unit has strengths and weaknesses, optimal styles of use, and corresponding units against which it is vulnerable or well-suited. Effective play is usually characterized by consideration of these attributes, as well as efficient resource management, strong defenses, and knowledge of the opponent's strategies. The game's interface consists of construction and command buttons (depending on the unit selected), unit status information, resource information on the production of Energy and Metal, and a minimap which gives an overview of the game's battlespace – the visibility of which may be hindered by fog of war, necessitating the use of radar or scout units. There are a few highly advanced units which are invaluable combat-wise, such as nuclear missile launchers which have enormous range and very high damage, as well as long-range artillery that have enough range to attack any point on smaller maps. There are two story-related factions, Arm and Core, which have comparable sets of units (one side a little bit faster, other one a little bit tougher etc.), but are aesthetically different. Generally, the Arm have faster, sleeker units while the Core units are built to take slightly more punishment. This is shown exceptionally well by the Arm being able to build an extremely fast Kbot known as the Zipper, while the Core can build an armored Kbot known simply as The Can. When playing amongst experienced players, subtle differences between the two factions put Core players at a disadvantage. The most noticeable differences are as follows: The level 1 Arm fighter aircraft is 1.7× more maneuverable than its Core counterpart, the Arm commander walks 1.12× faster than the Core commander, amphibious Arm Kbots float above water, making them faster and more useful than their submerging Core counterparts, Arm players can build Farks, fast assistant repair Kbots which can be crowded around labs and structures to dramatically reduce build times, and level 1 Arm tanks are equipped with superior weapons. Core has some distinct advantage as well, such as superior naval units, level 1 bombers that drop more bombs, and less conspicuous nuclear facilities. These advantages, however, are overshadowed by the Arm advantages in most situations.

Total Annihilation was one of the first RTS games to feature radar that showed enemy units within its radius on the minimap. This added an additional element of electronic warfare to the game: players could construct radar jammers that prevented units in a small radius around them from appearing on radar. Mobile radar jammers could be used to create surprise attacks, necessitating the deployment of scout units on a regular basis to reveal said units visually. In addition, radar jammers could disguise the presence of visually cloaked units, such as the commander or land mines. Radar fields rendered cloaked units detectable; a radar jammer could make said units undetectable until the radar jammer was destroyed. Total Annihilation was also one of the first RTS games to point the way towards battlefields with hundreds and thousands of units. Previous games could field a hundred units or so. Total Annihilation initially permitted 250 units per side which was later patched to 500. A third party patch allowed up to 5,000 units per side.