The couple, both retired, run a dance class at Weston Favell and were so bowled over by the school's new pound;1.3 million sports and function centre that they asked to have their wedding there in September.
Now they have secured a licence which allows the school to host the ceremony.
"We used to have a vaulting horse in our day and that was about it. Now they do weddings," said Mr Johnson.
The marriage licence is just the latest in a line of commercial innovations at the 1,300-pupil comprehensive run by the local authority, which has two bars on site and hosts at least one wedding reception a week.
Headteacher John Howard said revenues had reached pound;175,000 since the sports and function centre opened for business in October. An annual turnover of pound;500,000 was expected and any profit would be ploughed back into school buildings and resources.
The centre, which was paid for with a combination of Lottery money and the school's fundraising, also offers the public a library open until 10pm every evening, a cyber cafe, sports hall, gyms and classroom facilities.
The wedding sideline, Mr Howard said, was a natural extension: "We are led by demand and where there is a need we should meet it. Marriages are at the heart of any community and we want to be there during the joyous times as well as the educational times.
Although unusual, Weston Favell is not the first. Hinchingbrooke School in Huntingdon has been hosting weddings in its Sixth Form Centre, formerly Oliver Cromwell's house, since 1995.