  We present a scheme of positioning a single electron spin with sub-nanometer
resolution through multiple nitrogen-vacancy centers in diamond. With unwanted
noise suppressed by dynamical decoupling, the spin coherence of each center
develops characteristic oscillations due to a single electron spin located
$4{\sim20}$ nm away from the centers. We can extract the position information
from the characteristic electron spin-coherence oscillations of each center.
This scheme is useful for high-resolution nanoscale magnetometry and spin-based
quantum computing.
