Morrell Canyon Creek is a stream or Arroyo, tributary to San Juan Creek, located in the Cleveland National Forest in Riverside County, California, at an elevation of , in the Elsinore Mountains northeast of Elsinore Peak. It arises on the eastern slope of San Mateo Peak. An eastern fork draining the Morrell Potrero joins it a little over a mile north of its source and then flows northwestward about a third of a mile where it turns southeast descending the narrow Morrell Canyon east of Lion Spring. After descending 2.5 miles it turns north for half a mile then returns to a southwestern direction for another mile, the canyon widening here until it turns northwestward and down a steep canyon again for half a mile where it takes in from the right Decker Canyon Creek and Long Canyon Creek. It then turns southwestward again into a wider canyon and descends to its confluence with Bear Canyon Creek and becomes the head of San Juan Creek.