Division I is the highest level of college sports in the National Collegiate Athletic Association (NCAA) in the United States. Its schools generally have the biggest budgets, the best facilities, and offer more their students more athletic scholarships than Divisions II and III.

Below is a list of sports conferences belonging to Division I:

Football Bowl Subdivision
American Athletic Conference
Atlantic Coast Conference
Big Ten Conference
Big 12 Conference
Conference USA
Mid-American Conference
Mountain West Conference
Pacific-12 Conference	
Southeastern Conference
Sun Belt Conference

Football Championship Subdivision
Big Sky Conference
Big South Conference
Colonial Athletic Association
Ivy League
Mid-Eastern Athletic Conference
Northeast Conference
Ohio Valley Conference
Patriot League
Southern Conference
Southland Conference
Southwestern Athletic Conference

These conferences only play football:
Missouri Valley Football Conference
Pioneer Football League

Other conferences
These conferences do not play football, but do play basketball:
America East Conference
ASUN Conference
Atlantic 10 Conference
Big East Conference
Big West Conference
Horizon League
Metro Atlantic Athletic Conference
Missouri Valley Conference
The Summit League
West Coast Conference
Western Athletic Conference

These conferences play more than one sport, but do not play either football or basketball:
 Coastal Collegiate Sports Association (men's and women's swimming and diving, plus women's beach volleyball)
 Mountain Pacific Sports Federation

These conferences only play ice hockey:
 Atlantic Hockey (men only)
 Central Collegiate Hockey Association (men only)
 College Hockey America (women only)
 ECAC Hockey
 Hockey East
 National Collegiate Hockey Conference (men only)
 New England Women's Hockey Alliance
 Western Collegiate Hockey Association (women only)

The only Division I all-sports conference that plays either men's or women's ice hockey is the Big Ten. It started a men's hockey league in 2013–14.

These conferences only play water polo. All three run men's and women's leagues.
Collegiate Water Polo Association
Golden Coast Conference
Western Water Polo Association

One conference competes only in wrestling:
Eastern Intercollegiate Wrestling Association

These conferences play only one sport:
Eastern Association of Rowing Colleges
Pacific Coast Swim Conference

In some sports, the NCAA does not split schools into divisions because only a small number of schools play a given sport. Technically, conferences in these sports are not Division I. However, most of the schools in these conferences are in Division I in other sports.

These conferences only play men's volleyball (note that women's volleyball is split into divisions):
 Eastern Intercollegiate Volleyball Association
 Midwestern Intercollegiate Volleyball Association

These conferences only compete in skiing:
 Eastern Intercollegiate Ski Association
 Rocky Mountain Intercollegiate Ski Association

These conferences only compete in gymnastics:
 Eastern Intercollegiate Gymnastics League (men only)
 Midwest Independent Conference (women only)
 Mountain Rim Gymnastics Conference (women only)

These conferences only compete in rifle shooting:
 Great America Rifle Conference
 Mid-Atlantic Rifle Conference
 Patriot Rifle Conference

This conference only does fencing:
 Midwest Fencing Conference

This conference only does bowling (the ten-pin variety, which is an NCAA sport for women only):
 Southland Bowling League