Abstract: I will describe how topological entanglement of Chern-Simons theory is captured in a string theoretic realization. The Chern-Simons theory will be realized as the worldvolume dynamics of topological D-branes in the topological A-model string theory on a Calabi-Yau target. Via the open/closed topological string duality one can map this theory onto a pure closed topological A-model string. We will argue how to uplift the replica construction of Chern-Simons theory directly onto the closed string and show that the corresponding construction provides a meaningful definition of reduced density matrices in topological string theory.