  We have acquired a deep i-band image of the BL Lacertae object S5 0716+714
while the target was in an low optical state. Due to the faintness of the
nucleus, we were able to detect the underlying host galaxy. The host galaxy is
measured to have an I-band magnitude of 17.5 +- 0.5 and an effective radius of
(2.7 +- 0.8) arcsec. Using the host galaxy as a ``standard candle'', we derive
z = 0.31 +- 0.08 (1 sigma error) for the host galaxy of S5 0716+714. This
redshift is consistent with the redshift z = 0.26 determined by spectroscopy
for 3 galaxies close to S5 0716+714. The effective radius at z = 0.31 would be
12 +- 4 kpc, which is consistent with values obtained for BL Lac host galaxies.
An optical spectrum acquired during the same epoch shows no identifiable
spectral lines.
