  The Kepler light curve of DF Cyg is unparalleled in precision and cadence for
any RV Tau star to date spanning a baseline of $\sim$4 years and clearly
displaying the signature pulsating behavior of alternating deep and shallow
minima as well as the long-term trend indicative of an RVb-type variable. We
measured DF Cyg's formal period (the time interval between two successive deep
minima) to be $~49.84 \pm 0.02~$days. The trend in the arrival times emulates
that of the long-term period. There appears to be precisely 16 deep+shallow
minima cycles in one long-term cycle, suggesting a long-term cycle period of
$\approx$ $795 \pm 5~$days. We argue that binarity may naturally explain the
long-term periodicity in DF Cyg. The spectral energy distribution of DF Cyg
features an infrared excess indicative of a disk possibly linked to a binary
companion. From a recent Gaia parallax measurement for DF Cyg, we calculated
that it has a distance of $990 \pm 372$pc and a physical radius of $R_\star =
10.3 \pm 3.8$ R$_\odot$. From kinematics and geometric arguments, we argue that
the most likely interpretation for the decrease in flux from the long-period
maximum to the long-period minimum, as well as the reduction of short-term
pulsation amplitude, is caused by an occulting body such as a disk surrounding
DF Cyg and its binary companion.
