A reconnaissance probe was a type of probe that was used by Starfleet ships in the late-24th century.
Class 3 and class 5 probes have been used for reconnaissance missions. (DS9: "Valiant"; TNG: "Chain of Command, Part I"; VOY: "Blink of an Eye")
In 2370, Worf suggested that the USS Enterprise-D could launch reconnaissance probes to supplement their sensors, in the effort to locate the USS Fleming, lost in the Hekaras Corridor. Geordi La Forge however pointed out this wouldn't be effective, as the tetryon interference in the area made it difficult to maintain contact with the probes. (TNG: "Force of Nature")
In 2373, a high-resolution reconnaissance probe was launched from USS Voyager to study the clothing and physical appearance of the population of the Takar region on a planet in the Delta Quadrant. (VOY: "False Profits")