Ninety-nine YMCA leaders of individual YMCAs from Europe and North America met for the first time before the 1855 Paris World Exposition to discuss the possibility of joining together in a federation to enhance co-operation amongst individual YMCA societies. This meeting resulted in the Paris Basis which is still a guiding principle of the organization today. Two themes resonated during the council: the need to respect the local autonomy of YMCA societies, and that the purpose of the YMCA is to unite all young, male Christians for the extension and expansion of the Kingdom of God. The need for the respect of local autonomy is expressed in the preamble:

The YMCA's traditional symbol is the inverted triangle which represents the organization's three principles. It was created in 1891 by Luther Halsey Gulick, Jr. at Springfield College. The three principles are as follows.

The first YMCA was concerned with Bible study, although the organization has generally moved on to a more holistic approach to youth work. Around six years after its birth, an international YMCA conference in Paris decided that the objective of the organization should become "Christian discipleship developed through a program of religious, educational, social and physical activities" (Binfield 1973:265). More recent objectives as found on the YMCA UK website include no reference to discipleship.

Restore Ministries of the YMCA of Middle Tennessee provides an example of how the Christian influence in the YMCA still exists today. Founded in 2000 by Scott Reall, Restore provides support groups and individual counseling with an aim of “lifting the ‘C’” (of the YMCA).

Many colleges and universities owe their creation to the YMCA. Springfield College was founded in 1885 as an international training school for YMCA Professionals, while Sir George Williams University—one of the two schools that eventually became Concordia University—started from night courses offered at the Montreal YMCA. Northeastern University (Boston, Massachusetts) began out of a YMCA in Boston, and Franklin University began as the YMCA School of Commerce. Detroit College of Law, now the Michigan State University College of Law, was founded with a strong connection to the Detroit, Michigan YMCA. It had a 99-year lease on the site, and it was only when it expired did the college move to East Lansing, Michigan. YMCA pioneered the concept of night school, providing educational opportunities for people with full-time employment. Many YMCAs offer ESL programs, alternative high school, day care, and summer camp programs.

American high school students have a chance to participate in YMCA Youth and Government, wherein clubs of kids representing each YMCA community convene annually in their respective state legislatures to "take over the State Capitol for a day." YMCA Youth and Government helps teens learn about and participate in civics in a real-world setting.

In 1891, James Naismith, a Canadian, invented basketball while studying at the YMCA International Training School in Springfield, Massachusetts (later to be named Springfield College). Naismith had been asked to invent a new game in a desperate attempt to interest pupils in physical exercise. The game had to be interesting, easy to learn, and easy to play indoors in winter. Such an activity was needed both by the Training School and by YMCAs across the country. It was a success from the very first game. Naismith and his wife attended the 1936 Summer Olympics when basketball became one of the Olympic events. In 1895, William G. Morgan from the YMCA of Holyoke, Massachusetts, invented the sport of volleyball as a slower paced alternative sport, which the older Y members could participate in. In 1930, Juan Carlos Ceriani from the YMCA of Montevideo, Uruguay, invented the sport of futsal as a synthesis of three indoor sports, handball, basketball, and water polo, maintaining the motivation of the sport foot-ball (soccer) on playgrounds reduced.

All YMCA programs have a strong importance on the values of caring, honesty, respect, and responsibility. These core values were adopted formally by the YMCA of the United States in the early 1990s. They were developed to help teach children right from wrong.

A federated model of governance has created a diversity of YMCA programs and services, with YMCAs in different countries and communities offering vastly different programming in response to local community needs. In North America, the YMCA is sometimes perceived to be primarily a community sports facility; in Great Britain, the YMCA is sometimes perceived to be primarily a place for homeless young people; however, it offers a broad range of programs such as sports, personal fitness, child care, overnight camping, employment readiness programs, training programmes, advice services, immigrant services, conference centers and educational activities as methods of promoting positive values.

The Archives of the YMCA of the USA are located at the Kautz Family YMCA Archives, a unit of the University of Minnesota Libraries Department of Archives and Special Collections. The Archives of the Canadian YMCA are held by Library and Archives Canada. Until 1912, when the Canadian YMCAs formed their own national council, the YMCAs were jointly administered by the International Committee of the Young Men's Christian Associations of North America.