[7] In 1968, Montclair Academy and The Kimberley School began to merge, offering cross-registration for classes and shared social events.

The school has advanced technology, science labs supporting research-based learning, four gymnasiums, a swimming pool, auditoriums, a black box theatre, and the Upper School both a $3 million arts wing and a multimillion-dollar academic and technology wing.

There is an interscholastic athletic program, and fields competitive teams in over 25 sports that have won over 100 championships in the past 10 years.

[9] Students have access to fine and performing arts opportunities ranging from a tri-campus Strings Program, to mounting a full Shakespeare production in 7th grade, to making movies in the Upper School.

[13] A green roof on top of the Johnson Family Academic Center has a garden, composter, weather station, and learning space for students.

In 2009, Montclair Kimberley Academy was voted Best NJ Private School by parents in Bloomberg Businessweek.

The school additionally puts on an arts showcase in September, and one to two plays each year, in the fall and in the spring.

Montclair Kimberley Academy students are frequent recipients of Scholastic Art and Writing Awards.

[citation needed] In 2016, two students have won Rising Star Awards from the Paper Mill Playhouse.

[19] The Montclair Kimberley Academy Cougars[5] compete in the Super Essex Conference, which is comprised of public and private high schools in Essex County and operates under the supervision of the New Jersey State Interscholastic Athletic Association (NJSIAA).

[27] The MKA ice hockey team finished the 2006–07 season ranked in the top 20 in New Jersey but lost 2–1 to Paramus Catholic High School in the first round of the state playoffs.

In the spring of 2009, MKA named former MHS alumni and coach, Brack Healy, their new bench boss.

Citing professional advancement, Healy resigned from MKA after only one season behind the bench and took over as the head man at Fair Lawn High School.

The team capped off the season with a 4–2 victory over West Essex High School in the McInnis Cup championship.

The team also made it to the finals of the 2007 North Non-Public B state championship where they lost to Newark Academy 3–2.

The 2008 team would repeat their 2007 success by making it back to the finals of the North Non-Public B state championship in which they lost 3–2.

The 2004 team won the Tournament of Champions against runner-up West Morris Mendham High School.

[32] The 2004 team finished the season with a 24-0 record after defeating West Morris Mendham 4-1 to win the ToC.

On June 2, 2009, MKA defeated St. Mary of Rutherford by a score of 7–3 to win the North Non-Public B crown and clinch a spot in the overall state title game.

[41] In 2009, the team was NJSIAA Prep B state champions with a 2–1 win over Stuart Country Day School.

[42] In the 2005–06 season the MKA Wrestling team won their first Prep B state championship in the history of the school.

[43] The boys soccer team won the Non-Public Group B state championship in 2006 (against Wildwood Catholic High School in the finals of the tournament), 2011 (vs. Gill St. Bernard's School) and 2012 (vs. Gill St. Bernard's)[44] The boys' soccer team were Prep B State Champions and NJSIAA sectional finalists, and won North Parochial B and overall Non-Public B championship in 2006, the school's first-ever wins in the tournament.

[46] The Cougars' boys' lacrosse team won the 2007 Prep B state title, ending Morristown-Beard School's five-year win streak.

[47] Kyrie Irving, who was a Sophomore at the time, became the school's second 1,000 point scorer two days earlier in the semi-final game against top seeded and defending champion Solomon Schechter.

The boys lacrosse team won the Non-Public Group B state championship, defeating Pingry School in the tournament final.

This dominance not matched nearly by any other MKA sports program was led by coach Thomas Fleming until his death in the spring of 2017 where he suffered from a heart attack during a track meet.

The girls soccer team finished the 2017 season with a 17-4-5 record, after winning the Non-Public Group B state title as co-champion with Moorestown Friends School after a 3-3 tie in the finals of the tournament.