We report optical imaging and spectroscopy of 41 galaxies in a 22 arcmin square region surrounding Cygnus A .
The results show that there is an extensive rich cluster associated with Cygnus A of Abell richness at least 1 and possibly as high as 4 .
The velocity histogram has two peaks , one centered on Cygnus A , and a more significant peak redshifted by about 2060 km s ^ { -1 } from the velocity of Cygnus A .
The dynamical centroid of the spatial distribution is also shifted somewhat to the NW .
However , statistical tests show only weak evidence that there are two distinct clusters .
The entire system has a velocity dispersion of 1581 km s ^ { -1 } which is slightly larger than other , well studied , examples of rich clusters .

\keywords galaxies : active—galaxies : clusters : individual ( Cygnus A ) — galaxies : distances and redshifts—galaxies : individual ( Cygnus A )