The crime of theft, also known as stealing, thieving, or thievery, was the taking of another individual's property without permission. An individual who engaged in this activity was known as a thief. A minor form of this crime was petty theft.
In the 22nd century, Nausicaan pirates robbed ships of the Earth Cargo Service and stole their cargo. (ENT: "Fortunate Son")
In 2152, Trip Tucker told Jonathan Archer about how he was once falsely accused of stealing a pencil from his teacher's desk. (ENT: "A Night in Sickbay")
In 2263 of the alternate reality, the leader of the Teenaxi Delegation claimed to Captain James T. Kirk that a piece of the Abronath had been stolen by the Fibonans before it had been gifted to the Teenaxi. (Star Trek Beyond)
The Traitor's Claw was a stolen Kzinti police vessel. (TAS: "The Slaver Weapon")
Captain James T. Kirk and his crew were charged with theft after commandeering the USS Enterprise in order to retrieve Captain Spock from the Genesis Planet in 2286. The charge was eventually dismissed by the President of the Federation. (Star Trek IV: The Voyage Home)
Berlinghoff Rasmussen committed numerous thefts of small objects on the USS Enterprise-D in 2368. The stolen objects included a tricorder and a phaser. His intention was to return to 22nd century New Jersey in a time-pod he had stolen, and to then claim to have invented the items, in order to make a profit. His plans were thwarted by the Enterprise crew. Odo later recounted these events to Worf, as an example of a security breach under his tenure as security chief. (TNG: "A Matter Of Time"; DS9: "Bar Association")
In 2369, on Stardate 46682.4, a group of mercenaries boarded the USS Enterprise-D while is was powered down for a baryon sweep and attempted to steal trilithium resin from the warp core to be used in the production of a bomb with the intent to sell it to either the Maquis or Kohn-Ma terrorists. Captain Picard thwarted this plan and destroyed the container preventing it from being sold. (TNG: "Starship Mine")
Miles O'Brien told his wife Keiko, in 2371, that a case of medical supplies had been stolen from the Infirmary. (DS9: "The House of Quark")