  We describe Dalitz plots arising in studies of $D$-meson decays, and what we
have learned from them in recent years. After some mention of technique and
history, we focus on decay of the $D^\pm$ and $D_s^\pm$ mesons to the
$K^-K^+\pi^\pm$ final state, and on $D_s^\pm$ decay to $\pi^+\pi^-\pi^\pm$.
Some mention of other Dalitz plots involving $D$-meson decays is also made.
