In short, we're not 100% sure.

However, there are many hypotheses on the subject of who Elise actually is. I'd like to go back to the history of the piece itself to paint a picture for you.

The piece itself came to light in 1867, 40 years after Beethoven's death. It was discovered by Ludwig Nohl the then Professor of Music at the University of Munich who affirmed that the manuscript was original, autographed and dated 27/April/1810.^1

It has been suggested that Nohl made an error in transcription, Beethoven's sloppy handwriting and the effects of 40 years of wear, and the Elise in the title is actually Therese, most likely Therese Malfatti (1792-1851) who Beethoven proposed to in 1810.^2

There is also evidence that the Elise in question may have been Beethoven's friend Elisabeth Rockel, a German soprano singer of the time.^3 But this has been recently refuted (or at least seriously called into question) by the work of Austrian musicologist Michael Lorenz^4 who shows that this hypothesis (championed by Klaus Martin Kopitz) "is based on flimsy evidence and cannot be upheld.". Lorenz's paper is available in its entirety here.

It is also worth noting that despite the fact that the autographed copy of the score found by Nohl went instantly missing, rather than imply that Nohl fabricated the whole thing, score and all, there are two surviving sketches of Fur Elise that survive. You can see one of them here. These scores have been certified as original sketches, there is no doubt over who composed the piece, only who it is dedicated to. I hope this helped.

^1. William Kinderman, The Cambridge Companion to Beethoven, Cambridge: Cambridge University Press, 2000, p. 125–126

^2. "Beethoven and Therese von Malfatti," The Musical Quarterly 11, no. 1 (1925): 63–72.

^3. Klaus Martin Kopitz: Beethoven, Elisabeth Röckel und das Albumblatt "Für Elise", Köln: Dohr, 2010,

^4. Michael Lorenz: "'Die enttarnte Elise'. Die kurze Karriere der Elisabeth Röckel als Beethovens 'Elise'", Bonner Beethoven-Studien vol. 9, (Bonn 2011), 169–90.

This is somewhat related - does anyone know how Bach transcribed his music being blind? I would assume he just had someone to dictate the sheet music for him but idk

Might be more appropriate at /r/classicalmusic