Based on $(10087\pm 44)\times {10}^{6}J/\psi$ events collected with the BESIII detector at BEPCII, the double Dalitz decay ${\eta }^{\prime }\to e^{+}{e}^{-}{e}^{+}{e}^{-}$ is observed for the first time via the $J/\psi \to \gamma {\eta }^{\prime }$ decay process. The significance is found to be $5.7\sigma$ with systematic uncertainties taken into consideration. Its branching fraction is determined to be $B({\eta }^{\prime }\to e^{+}{e}^{-}{e}^{+}{e}^{-})=(4.5\pm 1.0(\mathrm{stat})\pm 0.5(\mathrm{sys}\left)\right)\times {10}^{-6}$.