The River Hodder is a river in Lancashire, England. The river is a County Biological Heritage Site.
It rises on White Hill and flows for approximately 23 miles to the River Ribble, of which it is the largest tributary. The confluence of the rivers is an impressive sight, particularly when both are in .
The Hodder drains much of the Forest of Bowland Area of Outstanding Natural Beauty and all but the last mile of its course is through this scenic area.
The upper reaches of the river feed the large , which provides much of Lancashire's water supply. After exiting the reservoir, the Hodder continues in a general southward direction. It collects many tributaries from the valleys of Bowland and, lower down, parts of the Ribble Valley. Most notable among the feeders of the Hodder are Croasdale Brook, Easington Brook, the River Dunsop, Langden Brook and the River Loud.
Much of the land in the Hodder Valley further to the north is owned by the Crown as Duke of Lancaster, whilst further down, farming land on the Stonyhurst Estate is owned by Stonyhurst College and the Jesuits. The river runs close to the College and passes adjacent to the former preparatory school, Hodder Place. The river lends its name to the pre-preparatory department at Stonyhurst, "Hodder House" and also years three to five known collectively as "Hodder Playroom".
The River Hodder eventually joins the River Ribble near Great Mitton, close to the River Calder.
The relief of the river starts over 400 m above sea level and within a distance of 15 km it drops to 99 m above sea level.