Moodna Creek is a small tributary of the Hudson River that drains eastern Orange County, New York. At 15.5 miles (25 km)^[1] in length from its source at the confluence of Cromline Creek and Otter Kill west of Washingtonville, it is the longest stream located entirely within the county.

Despite its small size relative to the Hudson, it has been a major influence on the topography of eastern central Orange County. Its 187.2-square mile (485 km²) watershed,^[1] including not only both its parent streams but Woodbury Creek as well, reaches as far inland as Goshen as well as 21 other area communities. Near Salisbury Mills it is crossed by the Moodna Viaduct, the longest actively-used railroad trestle east of the Mississippi.