Derivation On the same page

[spedlaw2]

What is the origin of the phrase "on the same page," and who coined the term and when?

[Quizmonster]

If you mean "thinking along the same lines" or "considering the same topic" as the rest of us, it probably originated in school classrooms long ago.
Thus, someone might say, "In maths lessons, I was never on the same page as the rest of the class." (Literally true in my own case! In log-books, they were always on the cosine page, for example, whilst I was on the tangent one.) This was then extended to refer to any situation where it was necessary to establish that all concerned were, in fact, doing what I suggested in my opening sentence.
Other variants of the saying appeared, such as, "Are we all singing from the same hymn-sheet?" and so on.

[Groupie]

Thank you Quiz I always thought it referred ti some one sexual tendency Silly me

[Quizmonster]

It may well have been used in that way, Groupie, but I've certainly never heard that. If a sexual connotation was common, I'd imagine it would have appeared in the Urban Dictionary, which is not at all shy about revealing such things! I had a look there, but the only meaning ascribed to the phrase is the one I provided earlier. Cheers