The 51-year-old, who started out in business selling slippers, shoes and trainers at The Barras in Glasgow before becoming Scotland's first self-made billionaire, has agreed to relaunch a new-look Castle Primary in New Cumnock, Ayrshire, which has just undergone a £9.6million makeover.
It was the first school Sir Tom went to and he readily agreed to be the guest of honour when a special ceremony is held on Monday to officially open it.
He is so thrilled he plans to hand over a surprise gift.
Education bosses decided to merge the village's two primaries because of falling pupil numbers.
Cairnhill Primary is being closed and youngsters from New Cumnock will all be taught at Castle Primary.
The refurbished school has a new gym and dining hall. Nine classrooms have also been modernised, while a linked nursery school has also been built.
The complex in Lanehead Terrace is being renamed New Cumnock Primary School.
It comes at a time when East Ayrshire Council plans to regenerate the village centre.
When the school was opened, a giant silver key was handed to pupils and teachers by council deputy leader councillor Tom Cook.
He said the new buildings were "a very visible sign of our clear commitment to investing in our communities".
Sir Tom is believed to be Castle Primary's most successful pupil. He lived in the village and went on to attend the local academy.
He started selling trainers from a stall at The Barras before launching his Sports Division retail chain.
He opened his first shop in Paisley in 1984 and, within 14 years, he had more than 250 stores across the UK and a workforce of 7500.
Sir Tom, who was knighted seven years ago, joined the ranks of the country's super rich when he sold his chain to rival JJB Sports in 1998 for a reputed £250million.
He then built up his fortune by investing in property and other retail companies, although this year he said he lost £250million overnight due to the credit crunch. He has also given away millions to charity.
The Ayrshire entrepreneur is backing a campaign by Glasgow refrigeration boss Sir Willie Haughey to persuade the country's business community to slash unemployment by recruiting jobless under 24-year-olds.
Sir Tom said: "I think unemployment is the scourge of any society. If we can't give the young people a job and purpose, it can lead to health and criminal justice problems.
"Once the pits closed in New Cumnock, I saw what happened there. There were no jobs and the community went through difficult times. So when Willie came up with this idea I thought this was something worth backing."