Faraday cages have traditionally been used to provide isolation from electromagnetic fields. In this paper, we describe the use of Faraday cages for reducing crosstalk in 3D ICs. We validate our methodology with a combination of simulation and measurements from fabricated prototype designs. Measurement and simulation results show that the crosstalk between the transmitter and receiver reduces by about 75 dB up to 10 GHz by using a Faraday cage in combination with tier-to-tier isolation, which is one of best performance reported so far. We further develop a lumped equivalent model for crosstalk with and without a Faraday cage. There is good agreement between measurement, 3D electromagnetic simulation and lumped circuit simulation.