As of the census of 2000, there were 150,336 people, 60,530 households, and 40,131 families residing in the county. The population density was 193 people per square mile (75/km²). There were 67,806 housing units at an average density of 87 per square mile (34/km²). The racial makeup of the county was 96.62% White, 2.09% African American, 0.08% Native American, 0.42% Asian, 0.01% Pacific Islander, 0.35% from other races, and 0.43% from two or more races. Hispanic or Latino of any race were 1.11% of the population. 29.0% were of German, 14.1% Irish, 9.7% Polish, 7.5% Italian, 5.6% American and 5.1% Lithuanian ancestry according to Census 2000. 95.7% spoke English and 1.2% Spanish as their first language.
There were 60,530 households out of which 26.80% had children under the age of 18 living with them, 51.40% were married couples living together, 10.20% had a female householder with no husband present, and 33.70% were non-families. 29.90% of all households were made up of individuals and 16.50% had someone living alone who was 65 years of age or older. The average household size was 2.36 and the average family size was 2.93.
In the county, the population was spread out with 20.90% under the age of 18, 7.20% from 18 to 24, 28.30% from 25 to 44, 23.80% from 45 to 64, and 19.90% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 99.10 males. For every 100 females age 18 and over, there were 97.20 males.
Schuylkill County is one of the most heavily Lithuanian parts of the United States. New Philadelphia, West Mahanoy, Shenandoah, and Girardville have the highest proportions of Lithuanian Americans of all places in the country. Also in Schuylkill County (as well as its neighbor to the north, Luzerne County) are Tyroleans, whose ancestors immigrated from the Tirol in northern Italy (at that time in Austria). Although they bore Italian surnames, the ancestors of the Tyroleans, who immigrated to the Coal Region in the late 19th and early 20th centuries, spoke German as their native language. The Tirolesi Alpini organization in Hazleton continues to preserve and promote Tyrolean culture. Irish Americans and Polish Americans are also predominant. The southern and western portions of Schuylkill County are predominantly Pennsylvania Dutch. This area, which includes the boroughs of Tremont, Schuylkill Haven, Cressona, Tower City, and Pine Grove, cannot really be considered the coal regions, as agriculture was the prevalent occupation.