The Cross County Trail is a multi-use trail that generally follows various stream valleys in Fairfax County, Virginia. It is officially named the Gerry Connolly Cross County Trail in recognition of Congressman Connolly's strong support for open space and parkland during his tenure on the Fairfax County Board of Supervisors. 

The entire length of the Cross County Trail is open to foot traffic and bikes. Some sections are too rough for road bikes, but mountain bikes and hybrids will have no problem.

The trail winds through northern Virginia's hardwood forests, much of it bottomland—as it follows stream courses that braid their way throughout the county. Some of the trail passes through the forest and meadows of county parks, while other sections pass through county-owned land that borders wooded subdivisions. In addition, trail users will find nearby shopping and business districts. A small portion of the trail follows the Washington & Old Dominion Trail.

The northern end begins in Great Falls National Park, at the legendary Potomac River. Heading south, the trail extends to the Occoquan River, passes through Laurel Hill, the site of the former Lorton Prison, now an expansive county park with lots to offer.