By definition, a transition element must have partially filled $d$-orbitals in its elemental state or its common ions.

• Zinc ($Zn$): At. No. $30$. Configuration is $[Ar]3d^{10}4s^2$.
• Ion ($Z{n}^{2+}$): Configuration is $[Ar]3d^{10}$.
• Since the $d$-subshell is completely filled in both states, Zinc does not show variable valency ($+2$ only) and does not show $d-d$ transitions (salt compounds are colorless). Thus, it lacks the 'typical' transition metal properties.