Suspect is an interactive fiction computer game designed by Dave Lebling and published by Infocom in 1984. It is the last murder mystery Infocom released, bringing an end to a popular genre of titles such as Deadline and The Witness. Like most Infocom titles, it was written in highly portable ZIL and made available for an array of popular computer platforms, including the Apple II, IBM PC, Atari ST, and Commodore 64. It is Infocom's fifteenth game.

The player's character is a reporter for the fictitious newspaper The Washington Representative. Veronica Ashcroft-Wellman, a longtime friend and wealthy socialite, has sent an invitation to the annual Ashcroft Halloween Ball, where Maryland's high society bluebloods rub elbows, network, and congratulate each other on their fortunes. The paper's editor suggests covering the party as a story, smelling an easy article that could either praise or mock the wealthy. Since it is a costume party, the player's character suits up in a rented cowboy outfit and moseys over to the bash. Many attendees wear masks, making it difficult to initially identify them.

Not long into the party, however, Veronica is found dead—strangled with a very familiar-looking lariat, with a bullet from the costume's gunbelt lying near the body for good measure. But the player stashed the rope in the closet earlier, and the bullet is missing from the back of the belt; anyone could have taken them! Nevertheless, the player is the prime suspect in Veronica's murder. A lot of snooping has to be done to identify the real killer...