  We determine the Grothendieck rings of the category of finite-dimensional
modules over Queer Lie superalgebras via their rings of characters. In
particular, we show that the ring of characters of the Queer Lie supergroup
$Q(n)$ is isomorphic to the ring of Laurent polynomials in $x_{1},\ldots,x_{n}$
for which the evaluation $x_{n-1}=-x_{n}=t$ is independent of $t$. We thus
complete the description of Grothendieck rings for all classical Lie
superalgebras.
