An inventor, also known as a creator or originator, was someone who created or designed new objects of technology.
Data, after having traveled back in time to 1893, claimed that he was an inventor upon being asked by Jack London. London had just agreed to use Data's money to purchase a list of items that Data intended to use to construct a device to detect shifts through time. (TNG: "Time's Arrow")
Berlinghoff Rasmussen was an inventor in the 22nd century from New Jersey. (TNG: "A Matter of Time")
Dr. Zefram Cochrane was credited as being the inventor of warp drive. (Star Trek: First Contact; ENT: "Broken Bow", "The Expanse", "Daedalus"; TOS: "Metamorphosis"; TNG: "New Ground"; VOY: "Year of Hell", "Homestead")
Richard Daystrom was the inventor of the comptronic and duotronic computer systems in the 23rd century. He was awarded the Zee-Magnees Prize and Nobel for the latter. (TOS: "The Ultimate Computer")
Sarah April created many of the tools eventually used in USS Enterprise's sickbay out of necessity. (TAS: "The Counter-Clock Incident")