The 23 surnames begin with O

Oldham (1)
Olivier (1)
Olsthoorn (3)
Onderwater (3)
Onnozel (1)
Oomen (2)
Oord (1)
Oosterveer (1)
Oostrom (2)
Op 't Root (2)
Opdam (1)
Opgemeld (1)
Otte (3)
Oudshoorn (1)
Ouwersloot (10)
Overbeck (1)
Overbeek (1)
Overdijk (4)
Overduin (2)
Overgaauw (1)
Overgauw (1)
Overmans (1)
Overmeer (2)