Timothy Pearce-Slade, of Bellerbys College, Cambridge, admitted kissing the girl in a "non-consensual" way, a National College for Teaching and Leadership disciplinary panel heard.
He has been banned from working in schools indefinitely.
The panel also considered allegations Pearce-Slade touched students from 2006 to 2012, but found them not proven.
Between September 2003 and January 2004, the panel heard, Pearce-Slade, 64, would often walk the teenager, named as Student A, home from school and kiss her cheek in parting.
On 5 January 2004, the teacher, who taught physiology and cell biology, offered to walk the pupil home after she had been feeling unwell.
When they arrived at her home, Pearce-Slade said to her: "I am going to give you a kiss on the lips".
Student A protested and tried to move her face, the panel heard, but Pearce-Slade held her shoulders and said words to the effect of "don't be silly".
He admitted the contact had been non-consensual and the panel concluded his actions were sexually motivated.
In a statement, Pearce-Slade said he allowed himself to get unprofessionally close to Student A and admitted he went a "step too far".
Following the allegations, independent Bellerbys College, which caters to pupils aged 15 to 21, dismissed him last July.
A biology teacher who kissed a student on the lips and cheek in a "sexually motivated" manner has been struck off.