Shrewsbury School has announced that Packwood Haugh Preparatory School will be joining its family of schools from September 2019.
David Stacey, chair of governors at Packwood Haugh, said the move would help the school fulfil ambitions to become the best of its type in the region.
He said: "We are delighted to be joining forces with Shrewsbury.
"Packwood Governors are committed to the continuing development of this highly regarded and much-loved school.
"Our vision is for Packwood to become the outstanding preparatory school in the West Midlands and beyond and we believe that the merger with Shrewsbury School is the best way to achieve this.
"Packwood and Shrewsbury already have close ties and with a very similar ethos the two schools are a natural fit.
"Packwood will retain its name and uniform and continue to prepare pupils for the next stage of their education, whether at Shrewsbury School or other senior schools throughout the UK.”
Leo Winkley, headmaster of Shrewsbury School, said the partnership would benefit both schools.
He said: "I am thrilled to welcome Packwood Haugh pupils, parents, staff, and alumni to the Shrewsbury School family.
"For well over a century, Packwood families have made the choice to pursue their children’s senior school education at Shrewsbury School.
"With almost 100 former Packwood pupils in the current Shrewsbury School community, we are delighted to formalise our relationship in this way.
"As two schools with a strong values and ethos match, the benefits of this mutually advantageous partnership will be significant for us all, as we offer girls and boys a fully immersive all-round boarding and day education which is forward-thinking and set on the secure foundations of tradition and history.”
The move means Packwood joins schools in Hong Kong and Bangkok, in becoming part of the Shrewsbury School family.
Parents can also register to attend the Packwood Haugh open day on May 18, or book a personal tour by contacting the school directly on 01939 260217.