The school's Anniesland campus will host a Glasgow Warriors Men's pre-season fixture ahead of the 2026/27 season, with fixture details to be confirmed.
As part of the agreement, the campus will also serve as an additional training venue for the Glasgow Warriors Women's team during next year's Celtic Challenge competition, alongside opportunities to host development fixtures and pathway activity across the school's facilities.
Glasgow Warriors Managing Director Kenny Brown said: "We're delighted to be partnering with The High School of Glasgow, a school with a strong sporting heritage and clear ambition.
"Access to facilities like Anniesland provides an excellent environment for our squads and it's particularly pleasing that this relationship will support the ongoing development of our Women's programme.
"We're also excited to be taking a pre-season fixture back out into the community. It's something we've seen real success with in the past and we look forward to revealing more about that fixture in the coming weeks."
Rector Antonia Berry said: "This partnership with Glasgow Warriors is an exciting step forward for sport at The High School of Glasgow.
"The fact that a professional side of their calibre has chosen to train and play at Anniesland is a strong endorsement of the quality of our facilities and the continued investment in sport at the school.
"As two long-standing Glasgow institutions, we share a commitment to excellence and I look forward to our collaborative working relationship flourishing over the coming years."