Foothills are geographically defined as gradual increases in hilly areas at the base of a mountain range. They are generally larger than hills, but not as tall as nearby mountains. Many neighborhoods and communities found in such a location are termed "the foothills".

Areas where foothills exist, or areas commonly referred to as the foothills, include:

• The Foothills of California in San Gabriel Valley in Los Angeles County, California
• The Colorado Front Range along the Rocky Mountains in Colorado
• The foothills of the Canadian Rocky Mountains in Alberta, Canada
• The Siwalik Hills along the Himalayas in the Indian subcontinent
• A rural farming community northeast of Spokane, Washington