We shipped support for installing the OneDrive app on an SD card, but any files taken offline still go to internal storage. We do have plan to enable offline files to be stored on SD card. I’ll update status as we get further along.Nigel Dyer commented
SD card for one Drive would be very much appreciated. Support may have been shipped on 1st Feb, but as if 16th Feb it is not an option on my Android phone. It is probably not possible to store the App on the SD card as this stops the widgets from working, but it should be possible to use the SD card for file storage. I have a number of other apps that do this just fine.