Shannon Creek is a short tributary to the Baker River in Whatcom County, Washington, near the southwest border of North Cascades National Park. It rises in two forks a few miles south of Mount Shuksan; the glacier-fed north fork begins at elevation , and the non-glacial south fork begins at . Roughly halfway through its length, the two forks join and then flow into Baker Lake reservoir, at elevation . Shannon Creek joins the Baker several miles downstream of Sulphide Creek and upstream of Swift Creek, a much larger south-flowing drainage.