Tom Clancy's Splinter Cell is a series of action-adventure stealth games, the first of which was released in 2002, and their tie-in novels that were endorsed by Tom Clancy. The series follows Sam Fisher, a highly trained agent of a fictional black-ops sub-division within the NSA, dubbed "Third Echelon", as he overcomes his adversaries. The games emphasize light and darkness as gameplay elements.

There have been six main games in the series: Splinter Cell (2002), Pandora Tomorrow (2004), Chaos Theory (2005), Double Agent (2006), Conviction (2010) and Blacklist (2013). Additionally, Essentials, a PlayStation Portable exclusive, was released in 2006 and Classic Trilogy HD, a remastered compilation of the first three games, was released for the PlayStation 3 in 2011. A remake of the first game is in development. Nine tie-in novels have been released. An eight-episode audio drama, Splinter Cell: Firewall, debuted in December 2022 and an animated series, Splinter Cell: Deathwatch, premiered on Netflix in October 2025.

The series has been positively received, and was once considered to be one of Ubisoft's flagship franchises. The series had sold 19 million units by 2008 and 32 million by 2016.

Tom Clancy's Splinter Cell was developed over a period of two years and developed by Ubisoft Montreal with original publishing by Microsoft Game Studios for the Xbox as an exclusive title. Later in 2003, Ubisoft ported the game to Microsoft Windows, Mac, PlayStation 2, GameCube, and Game Boy Advance. Inspired by the Metal Gear series, it uses an Unreal Engine 2 that was modified to allow light-and-dark based gameplay.

Pandora Tomorrow was developed by Ubisoft Shanghai and Ubisoft Milan and introduced multiplayer gameplay to the series. In single-player mode, the game AI adapts to adjust to the player's skill level. Unlike other games in the series, which generally lean towards information-based threats, the plot of Pandora Tomorrow focuses on biological warfare, in which an Indonesian terrorist group threatens to infect people with the smallpox virus. Fisher is also given new abilities like SWAT turns and whistling to attract enemies' attention. It also introduced a revolutionary new online mode called spies versus mercenaries, in which one team would play from a third person perspective on the spy team, and the more guns-blazing first-person perspective of the mercenaries.

Ubisoft Montreal and Ubisoft Milan were again responsible for the third game in the series, Chaos Theory. It adds a cooperative multiplayer mode. Originally announced to be released in Fall 2004, its initial releases were made at the end of March 2005. The Unreal Engine was heavily modified, this time from version 2.5. The game includes a number of new features, including adding a combat knife to the player's inventory. Maps are also more open with multiple ways of achieving the end goal.

Essentials extends the Splinter Cell series to the PlayStation Portable. Through a series of flashback missions, the player learns more about Fisher's backstory. The game was less positively received critically than previous installments, with criticism aimed at the control mechanics and the multiplayer mode.

For the series' fourth installment, Double Agent, two separate versions were created, one for generation six consoles and the Wii, and the other for Xbox 360, Microsoft Windows, and PlayStation 3. Double Agent features a "trust system" that presents the player with moral dilemmas. It is the first game in the series with a hub-like area, where Sam can explore and do objectives between missions. This is also the only game in the series to have different endings based on player decisions, but only one ending is considered canon.