The school was founded in 1960 by educator Russell G. Ranney to help improve students' college board grades.

[15][16] The school has won more than 30 individual and team championships in five years, including swimming, tennis, basketball, fencing, and more.

[19] The boys' basketball team won the Non-Public Group B state championship in 2019, defeating Roselle Catholic High School by a score of 56-50 in the tournament final at the RWJBarnabas Health Arena, having lost to Roselle Catholic in the Non-Public B finals a year before on a last-second basket.

[20][21] Ranney came into its first Tournament of Champions as the top seed, winning against number-five seed Moorestown High School by 62-40 in the semifinals and won vs. second-seeded Bergen Catholic High School in the championship game by a score of 67-63 to finish the season with a 31-3 record.

[24] Professionally, Lasda has competed in multiple World Championships with the Latvian Women's National Lacrosse Team as a player and assistant coach since 2013 when she first began at Ranney.

[25] The 60-acre (24 ha) campus features assembly spaces and media centers, a music wing, two dining halls, two libraries, robotics labs, Innovation Labs (makerspaces), a finance lab featuring 12 Bloomberg terminals,[26] and athletic facilities including tennis courts, a track, two gymnasiums, an indoor 25-meter swimming pool, a 415-capacity outdoor grandstand and press box, training and conditioning facilities and fields for soccer, lacrosse, baseball, and softball.