Rikkyo maintains contact with more than 140 educational institutions abroad for the purpose of exchanging lecturers, students and projects.

With funding from the Domestic and Foreign Mission Society of the Protestant Episcopal Church and, in 1880, a new principal, James McDonald Gardiner[6] to supervise, new three-story brick facilities with an imposing 60-foot spire were constructed.

Enrollment jumped, but the school buildings were in a poor state of repair and were condemned as unsafe by government inspectors.

Less than three weeks after his return to Tokyo an earthquake in 1894 leveled much of the original school facilities, highlighting the perils of building on reclaimed land next to the Sumida River.

In 1909, 23 acres of land were purchased near Ikebukuro for the construction of a larger dedicated campus and the university moved into new buildings at this site in 1919.

The original, red-brick, campus buildings, designed by Murphy & Dana Architects of New York, suffered structural damage in the 1923 Great Kantō earthquake but, due to the university's more suburban location, escaped the fires that destroyed much of the center of the city.

Until the 1920s almost all classes at Rikkyo were held in English;[10] Japanese language textbooks were made more widely available toward the end of the decade.

In the late 1930s and during the Second World War Rikkyo's status as an Anglican Christian university came under severe pressure from the military authorities.

[11] In September 1942, university trustees agreed to change the wording of the charter to sever all ties with Christianity.

The majority of Christian faculty members lost their positions and the University All Saints Chapel was closed.

Occupation authorities moved swiftly to remove head officials associated with the teaching of militarism and the violation of the university's founding charter.

With contributions from private donors, the Episcopal Church in the United States and the Japanese Ministry of Education, between 1961 and 2001 the university owned and operated a TRIGA 100kW research reactor at Yokosuka, Kanagawa contributing the development of neutron radiography and energy research in Japan.

The original building was named in memory of Samuel Mather an American industrialist and long-time sponsor of Episcopal Church overseas mission work.