  We have obtained a deep i-band image of the blazar 3C 279 while the target
was in a low optical state. Due to the faintness of the optical nucleus we have
made the first detection of the host galaxy. The host galaxy has an apparent
I-band magnitude of 18.4 +- 0.3 and an effective radius of (2.7 +- 1.1) arcsec.
The luminosity of the host galaxy M_R = -23.8 is consistent with the
luminosities of other radio-loud quasar host galaxies. Using the empirical
correlation between bulge luminosity and central black hole mass M_bh we
estimate log(M_bh/M_Sun) = 8.9 +- 0.5, broadly consistent with values obtained
by photoionization methods.
