Joshim Nur was 22 when he began teaching at the London Nautical School, Lambeth, in 2006, a teaching disciplinary panel heard.
Nur, now 34, claimed he thought the girl was 18 but a written statement from the girl showed she had told him her age before the arranged marriage.
He also had a sexual relationship with the child, the panel heard.
He flew to Bangladesh during a summer break and returned to the UK with the girl, named by the panel as Child A.
In evidence, the girl told a Teaching Regulation Agency panel that sexual activity started shortly after her marriage to Nur in the summer of 2006.
She also confirmed that she was taken to an appointment at a family planning clinic in 2007 and that she took contraceptive pills every day.
The panel ruled that the Nur had a relationship with the girl from August 2006 to April 2009 in “circumstances when he should have known she was under the age of 16”.
Three days before the wedding, the girl had written to Nur to tell him she was 13 and in year 8 at school, the panel heard, the BBC reported.
In written evidence, Nur said that he was ‘”deceived” by the girl’s family as to his wife’s age when they wed.
Panel chairman Dr Robert Cawley said: “The panel did not find it plausible that Mr Nur could have mistaken a 13-year-old child for an 18-year-old, and that this misconception continued over a four-year period.
“The panel was particularly concerned in light of the fact that he worked in a secondary school and had daily interactions with children of this age.”
Nur was found guilty of engaging in a relationship with the child and of having sex on more than one occasion when she was under 16 – charges he denied.
The relationship ended in 2009, when the girl was 16.
Nur’s headteacher told the panel he was a “good teacher” and a “gifted and valued member of staff”.
The ruling branded Nur’s behaviour as lacking “any insight into his actions or their impact on Child A.”
Decision maker Alan Meyrick said: “In my judgement, the lack of insight means that there is some risk of the repetition of this behaviour.”
He then prohibited Nur from teaching indefinitely and said he shall not be entitled to apply for restoration of his eligibility to teach.
Nur is not being prosecuted as the marriage took place abroad, not under the UK jurisdiction, the Daily Express reported.