Fill it in with plastic wood or outdoor spackle and paint the door, which looks like it needs it anyway.
Right diameter wood dowel cut to fit depth of hole; wood glue, wood putty for screw holes, sand and paint. Might that work?
For as high -traffic and is sublet to being slammed closed I would use bondo
Rather than plastic wood (which will crack) or a dowel cutoff (which will expose end grain) I'd use the plug generated by an appropriately sized hole saw, aligning the grain.
I liked the idea of a brass rosette! I bet you could find something in one of the catalogs for interesting hardware.
Hey all - looking for creative ideas to fix this hole in front door - where previous owner removed a lock. Maybe some sort of brass rosette or small wooden medallion ? Thanks