Andrew Copas, 53, has had his Teachers' Pension Scheme boosted by pound;105,527 after being mis-sold a policy in 1988.
Mr Copas, a member of Kent's advisory team for special needs, had nearly 16 years of pension contributions in his fund when he transferred to a private scheme, held by Irish LifeCity of Westminster Assurance.
The new fund, however, proved to be a money loser and Mr Copas re-joined the Teachers' Pension Scheme in 1994. It has taken him more than two years to win his case and to have his teachers' fund restored to the level it would have been but for the mis-selling, with the company making up the difference.
He said: "I was gobsmacked when the notification came through. I'm still rather concerned that I won't have enough to manage on in the future, but this is a relief, to put it mildly.
"The person who sold me the pension was a friend, and I think he sold it to me in good faith, but I lost out and I'm just pleased the notification came through."
More than 20,000 teacher victims of mis-selling have sought compensation after they were wrongly persuaded to leave the Teachers' Pension Scheme and take out a personal pension.
Mr Copas's compensation is the largest to be won by his union, the Association of Teachers and Lecturers, which has so far secured a total of pound;5 million for 220 teachers who were victims of mis-selling. It is still fighting cases for 45 members.
The National Association of Schoolmasters Union of Women Teachers said it had secured a similar amount of money. The National Union of Teachers said it had won pound;15m for some 1,000 staff.
Peter Smith ATL general secretary, said:"The situation is still extremely serious for thousands of teachers and other public-sector workers who were so blatantly mis-sold pensions. The independent financial advisers must be required to continue to identify these financial victims and compensate them more quickly."
A spokesman for City of Westminster Assurance said that it was not possible to comment on the specifics of Mr Copas's case.