The county is bordered by Bong County to the south and Gbarpolu County to the west. The northwestern parts of Lofa border the nation of Sierra Leone and the northeastern parts border Guinea. Mount Wuteve, the highest mountain in Liberia, lies in the north-central part of the county. As of the 1984 Census, the county had a population of 199,242. Many people left the area as refugees in 1999 and the early 2000s as it became a main focus of fighting during the Liberian civil war. The Red Cross said that in January 2004 many people had begun to return from refugee camps in neighbouring Guinea and Sierra Leone.  At that time the county's population was estimated to be 34,310.

The largest city and county capital is Voinjama with a population of 4,945. Foya is the second largest city (population 1,760). Lofa produced one of the nations most respected leaders in the late vice president Dr. Harry F. Moniba who served from 1984 - 1990. Hon. Joseph Nyuma Boakai, Vice President of the Republic of Liberia Since 2006, is from Lofa County.