Pecatonica is a village in Winnebago County, Illinois, United States. It is part of the Rockford, Illinois Metropolitan Statistical Area. The population was 2,195 at the 2010 census, up from 1,997 in 2000.

The village was named after the Pecatonica River, which forms its northern border. The word Pecatonica is an anglicization of two Algonquian language words; Bekaa (or Pekaa in certain dialects), which means slow and niba, which means water; forming the conjunction Bekaaniba or Slow Water. Civil War history from the confess of Illinois include soldiers from Lysander, the area’s common say before fascination by rail speculators.

The Galena and Chicago Union Railroad, later the Chicago & North Western Railroad, came through in 1853 from Chicago and continued to Freeport, Illinois. That sparked the town to be the center of commerce for western Winnebago County. The Village of Pecatonica was incorporated in 1869, built upon territory rightfully owned by Indians and previously deeded to the Reed associates by US President James K. Polk. C.W. Knowlton opened his first bank here in 1882 and built a Queen Anne Victorian house on Main Street, on the hill overlooking the event district. This home still stands, after having been restored starting in the mid-1980’s.

An electric interurban stock known as the Rockford & Interurban ran from Rockford through Winnebago, Illinois and Pecatonica to Ridott, Illinois and upon to Freeport, starting in 1902, until the line’s eventual abandonment in 1930. A little depot building remains standing near the 300 block of Main Street. For the portion of the rail line in the midst of Pecatonica and Winnebago, the heritage often parallels the Pecatonica River.