A second classroom building was built, now demolished to make way for the Richard and Elizabeth Tudor Centre for Contemporary Learning.

At the beginning of the 1970s, Trinity purchased land beside Lake Eppalock, near Bendigo, opening the Leppitt Outdoor Education Centre in 1973, named after the headmaster.

As a result of new buildings constructed over the previous two decades, the school sought further land for outdoor sports facilities.

Trinity purchased land in Bulleen, near the Yarra River, and opened the Marles Playing Fields there in 1983.

The tuck shop, the original canteen, was closed in 1990 and a new cafeteria opened on the ground floor of the Shann Building.

[1] The school was interested in the development of curriculum and saw the possibilities being opened up in business and industry by the use of computer technology.

Nearby MLC had recently introduced laptop computers for the personal use by the students as an everyday part of their learning.

Trinity decided to use a business model and became the first school in the world to adopt the use of Microsoft Office within an educational setting.

Peter Crawley resigned in the same year accepting the position as headmaster of Knox Grammar School in Sydney.

The school opened a new gymnasium, the Peter McIntyre Sports Centre, to complement the old Cornell Sports Gym, and another block of forested land was purchased at Licola, to complement the Outdoor Education Centre at Lake Eppalock.

In 2005 the school also purchased the former Bib Stillwell car dealership showroom, on the corner of Charles Street and Cotham Road, which is currently used as a multipurpose venue, with impending development of the site in the future.

In 2011, the Poynter Building was demolished to make room for the Richard and Elizabeth Tudor Centre for Contemporary Learning.

[6] Towards the end of 2015 the school undertook the demolition of Arnold Hall (to be replaced by the Centre for Business & Social Enterprise).

The school also introduced Cambridge University's International General Certificate of Secondary Education (IGCSE) in Years 9 and 10 English.

"[13] In March 2019, Trinity announced that Adrian Farrer, principal of Cathedral College Wangaratta, would commence in 2020 as the school's 12th headmaster.

About the House Patrons: Trinity is highly regarded for its outreach and social justice programs, which are organised under the aegis of Harambee (a Swahili word meaning "all together").

Activities include immersion trips to Africa and Outback Australia, working with community organisations focused on mental illness, and a variety of fundraising events for numerous causes.

The Outdoor Education program includes participation in bushwalking, sailing, canoeing, kayaking, cycling, first aid, navigation, cooking and rafting.

Trinity was a founding and is a continuing member of the Associated Grammar Schools of Victoria (AGSV).

This action, which was described as "stupid and insensitive" by lawyers representing Howell's victims, attracted a great deal of controversy to the school.

"There is too much inward focus on things like buildings, fundraising, marketing, ATAR excellence, Cambridge schooling program, etc," Baumgartner wrote in his open letter which made its way to hundreds of parents' inboxes.

A large portion of the school community – including a representative of the student whose hair was cut – demanded that Brown be reinstated.

[22]Both Roderick Lyle (the school council chairman) and Michael Davies promised to consider the issue and reflect on the necessary actions.

However, the appointment of Utter sparked only more controversy as it was viewed by many that Utter was an unacceptable choice for chairman as he was an existing council member prior to the incident, that he was partially responsible for the "cultural shift" that the school had faced in recent years, and that – after 24 years on the council – he was no longer connected with the school community.

[11] Then, on 15 May, Michael Davies announced his resignation from the role of headmaster, sending out a letter stating that it came "after a great deal of thought and discussion with [his] family".

A former principal of Carey Baptist Grammar School, Phil De Young, was appointed interim headmaster until a permanent one could be found.