Richard Stanley sent messages to the young woman calling her 'hun' and asked her to rate her own appearance out of ten.
A professional conduct panel heard how 49-year-old Mr Stanley sent messages to the former pupil stating that he would 'go to the end of the world for her'.
Mr Stanley, a former teacher at The Cooperative Academy, Burmantofts, told her he was jealous when he saw her talking to another man.
In other messages he talked about an occasion when he kissed another woman.
The humanities teacher also told her loved her and/or loved spending time with her.
A professional conduct panel of the Teaching Regulation Agency (TRA) ordered that Mr Stanley be prohibited from teaching in any school, sixth form college, relevant youth accommodation or children’s home in England for an indefinite period.
The panel concluded that Mr Stanley's behaviour amounted to 'unacceptable professional misconduct'
Mr Stanley provided a signed statement of agreed facts to the panel admitting unacceptable professional conduct and/or conduct that may bring the profession into disrepute.
The panel found he failed to maintain professional boundaries with the woman, referred to as 'Former-Pupil A', who he had first met while employed as a teacher at her school
Mr Stanley messaged Pupil A via social media between approximately August to December 2018.
A document published online by the TRA states Mr Stanley was employed at Cooperative Academy from September 2005 to April 2019 as a humanities teacher.
Pupil A attended Cooperative Academy between 2011 and 2016 and Mr Stanley was previously her teacher.
Mr Stanley also volunteered at the LIFE Church in Bradford where he was a Sunday school leader.
In or around August 2018, Mr Stanley exchanged messages with Pupil A privately on Instagram.
The messages contained comments on Pupil A’s appearance and indicated a close relationship between them.
On 15 April 2019, Mr Stanley began employment at Springwell Leeds Academy as a humanities teacher.
In or around April 2019, a parent of a friend of Pupil A contacted the LIFE Church raising concerns about the private messages between Mr Stanley and Pupil A.
The LIFE Church referred the matter to the Local Authority Designated Officer (LADO) who conducted an investigation.
On 24 June 2019 Mr Stanley resigned from Springwell Leeds Academy and a disciplinary hearing took place at the school the next day.
The panel was satisfied that on at least one occasion Mr Stanley took Pupil A for a walk around a park on a drive to her home.
He also invited her to visit him at the school.
The report states: "The panel considered that this demonstrated that such a journey was not for convenience or may not have been necessary because of bad weather, but that it demonstrated a potentially inappropriate relationship between a teacher and an ex-pupil.
"The panel was satisfied that the allegation was proven."
Explaining the panel's decision, the document states: "The panel took into account the way the teaching profession is viewed by others and considered the influence that teachers may have on pupils, parents and others in the community.
"The panel also took account of the uniquely influential role that teachers can hold in pupils’ lives and the fact that pupils must be able to view teachers as role models in the way they behave.
"The findings of misconduct were serious and the conduct displayed would be likely to have a negative impact on the individual’s status as a teacher, potentially damaging the public perception.
"The panel therefore found that Mr Stanley’s actions constituted conduct that may bring the profession into disrepute.
"Having found the facts of the allegations proved, the panel further found that Mr Stanley’s conduct amounted to both unacceptable professional conduct and conduct that may bring the profession into disrepute."
The panel took mitigating factors into consideration, including Mr Stanley's previous good history as a long-serving teacher, his experience as a senior pastoral teacher and his responsibility for students with challenging behaviours and circumstances.
The panel considered that Mr Stanley did show some remorse for his actions but that, to date, had taken no positive steps in order to avoid similar issues arising again, such as training and/or counselling.
Mr Stanley may apply for the prohibition order to be lifted, but not until 14 January 2023.
The report states: "This is not an automatic right to have the prohibition order removed.
"If he does apply, a panel will meet to consider whether the prohibition order should be set aside. Without a successful application, Mr Richard Stanley remains prohibited from teaching indefinitely."