Starfleet I: The War Begins is a 1984 strategy computer game designed by Trevor Sorensen and developed by Interstel (some versions by Cygnus Multimedia). It was released for Apple II, DOS and Commodore 64. Versions for the Commodore 128 (bundled together as Commodore 64/128, though it included a discrete version for the 128 with 80-column support,) Atari ST and Atari 8-bit were released in 1986 and versions for the Amiga and Macintosh were released in 1987. The game was successful enough to spawn sequels which are collectively known as the Star Fleet series.

The game resembles the Star Trek text game. The player is a new graduate of Starfleet Academy in command of a starship. The Federation is at war with the Krellans and Zaldrons, so the player has plenty of combatants to engage from the beginning. Eschewing digital graphics, Star Fleet I presents all its information in color ASCII characters. Gameplay centers on two main activities: navigation and combat. Navigation takes place on the Main Computer GUI. It consists of a main star chart map, the player's current position, and visual displays. Other information may be accessed using appropriate commands. Navigation may be conducted manually or automatically