A professional conduct panel stated that Joshua Reed committed serious sexual misconduct and had used his professional position to exploit a pupil.
The decision to ban him from teaching has been supported by the schools trust which Haven High is part of.
The panel found Reed, 32, exploited the pupil by developing a sexual relationship with her between March 2014 and April 2015.
It stated that his actions had an adverse impact on the girl, known as Pupil A in the panel’s report, both at the time and since the misconduct happened.
Reed was first employed as a music teacher at Haven High Academy in 2010, and from September 2016 until his dismissal in March 2019, he was assistant head of the music faculty.
The school is now part of the Voyage Education Partnership, and it’s chief executive officer Emma Hadley said: "At Voyage Education Partnership, the safeguarding and welfare of our pupils is our highest priority.
“The proven allegations raised against Mr Reed between 2014 and 2015 represent behaviours that have absolutely no place within our organisation or the wider profession.
"We fully support the Secretary of State’s decision that Mr Reed is prohibited from teaching indefinitely."
The catalogue of misconduct admitted by Reed included engaging in sexual activity with the girl on a number of occasions, entering her home, going into a ladies toilets with her, and driving her to a local woods.
He also exchanged inappropriate messages with her, including asking her to send images of herself with her top pulled down and discussion about sexual activity with her.
Reed also sent messages to Pupil A asking her to keep quiet about their relationship and delete messages between them.
The report states: “The panel was satisfied that the conduct of Mr Reed fell significantly short of the standards expected of the profession.
“He took advantage of one of his pupils by developing a sexual relationship with her. This included sexual conduct and activity when she was under the influence of alcohol, and therefore vulnerable.
“As a teacher he should have taken steps to safeguard her and protect her rights, but instead, he took advantage of her for his own sexual gratification.
“When his conduct was first noticed by others, he sought to cover it up and instructed Pupil A to do the same. He was not open and honest during the initial investigation, and concealed the full extent of his misconduct.
“He then went on to continue the relationship, despite having been given advice by the School not to be alone with Pupil A or exchange mobile numbers with her. His unprofessional conduct lasted for over a year, and had an adverse impact on Pupil A's well-being both at the time and subsequently.”
In its recommendation that he be banned from teaching indefinitely with no provision for a review period, the panel said: “Mr Reed was responsible for serious sexual misconduct which resulted in or had the potential to result in harm to Pupil A, had used his professional position to influence or exploit her, and been dishonest about his conduct.”
The recommendation was accepted and the Secretary of State also stated that Reed would not be entitled to apply for restoration of his ability to teach.