In this paper, we obtain boundary Harnack estimates and comparison theorem for nonnegative solutions to the linearized Monge-Amp\`ere equations under natural assumptions on the domain, Monge-Amp\`ere measures and boundary data. Our results are boundary versions of Caffarelli and Guti\'errez's interior Harnack inequality for the linearized Monge-Amp\`ere equations. As an application, we obtain sharp upper bound and global \(L^p\)-integrability for the Green's function of the linearized Monge-Amp\`ere operator.