The women's 100m freestyle S12 event at the 2012 Summer Paralympics took place at the London Aquatics Centre on 4 September.

There were three heats; the swimmers with the eight fastest times advanced to the final.

'Q = qualified for final.

WR = World Record.

Official London 2012 Paralympics Results: Heats Archived 2012-09-13 at the Wayback Machine Official London 2012 Paralympics Results: Final Archived 2012-09-13 at the Wayback Machine