  Using color-kinematics duality, we construct for the first time the full
integrand of the five-loop Sudakov form factor in N=4 super-Yang-Mills theory,
including non-planar contributions. This result also provides a first
manifestation of the color-kinematics duality at five loops. The integrand is
explicitly ultraviolet finite when D<26/5, coincident with the known finiteness
bound for amplitudes. If the double-copy method could be applied to the form
factor, this would indicate an interesting ultraviolet finiteness bound for N=8
supergravity at five loops. The result is also expected to provide an essential
input for computing the five-loop non-planar cusp anomalous dimension.
