The Kellenberg Memorial High School seal depicts the torch of learning surrounded by a crown. The crown recalls Bishop Kellenberg's motto, Regina Verte Lumina -- "Queen, guide us with your light." The large letter M is a reminder that the Bishop was consecrated during the First Marian Year and the school was founded in his memory during the Second Marian Year in 1987. The shell is from Bishop Kellenberg's device and stands for Long Island, which was once called "the island of shells." The lamb is the symbol of St. Agnes, virgin and martyr, the patroness of the diocese. The motto, "One Heart and One Mind", expresses the goal of the school to educate both the mind and the heart of each student.

Kellenberg Memorial High School is named in honor of Most Rev. Walter P. Kellenberg, founding Bishop of the Diocese of Rockville Centre. He had a particularly strong devotion to the Blessed Virgin Mary. Both in his preaching and his example, he sought to bring all under the protection of Our Lady. The Bishop was a strong supporter of Catholic education, as evidenced by his extensive building program for the school system of the diocese.

The school is owned and directed by the Society of Mary (Marianists), a religious order of priests and Brothers. The Marianists were founded in 1817 by Venerable William Joseph Chaminade to educate youth as a means of Christianize society.

In September, 1987, the Administration of Kellenberg Memorial High School announced the establishment of the Bro. Joseph C. Fox Latin School. The Latin School is named in honor of a Marianist brother, Bro. Joseph C. Fox, who taught for over fifty years in Catholic schools. This new division of KMHS will provide a qualitative Catholic education to students from the public schools in grades six through eight.

The school's motto is "One Heart and One Mind". Its colors are royal blue and gold; its emblem is the phoenix; and its nickname is "The Firebirds."

Kellenberg Memorial High School combines the proven curriculum and methods of a successful tradition with modern pedagogical advances to provide its students with a rich, qualitative educational experience. The Kellenberg Memorial High School program, offered in an atmosphere of positive Christian commitment, requires a thorough study of the basic intellectual disciplines, while offering extensive cocurricular and extracurricular opportunities for practical application and personal understanding.

Kellenberg Memorial High School admits students of any race, color, sex national or ethnic origin to all the rights, privileges, programs and activities of the school. It does not discriminate on the basis of race, color, sex, disabilities, national or ethnic origin in the administration of its educational policies, admissions policies, financial policies, activities, athletics or other school administered programs. Kellenberg Memorial High School welcomes students of all ethnic groups, recognizing their valuable contribution to the life of the school in particular and the nation in general.

Kellenberg Memorial High School is a Catholic coeducational school. It was founded to serve the Catholics of Long Island and has enjoyed their support and assistance. Accordingly, priority in admissions is given to baptized members of the Roman Catholic Church. Enrollment is open to young men and women who are professing Christians as resources permit, with the priority given to Catholic students.