Clock skew compensation with adaptive body biasing in three-dimensional (3D) integrated circuits (ICs) (3DICs) is disclosed. In one aspect, a sensor is placed on each tier of a 3DIC to evaluate a speed characteristic of each tier relative to the speed characteristic of another tier. Based on determining the relative speed characteristics, a control signal may be provided to adjust back body bias elements for clock buffers. Adjusting the back body bias effectively adjusts a threshold voltage of the clock buffers. Adjusting the threshold voltage of the clock buffers has the effect of slowing down or speeding up the clock buffers. For example, slow clock buffers may be sped up by providing a forward body bias and fast clock buffers may be slowed down by providing a reverse body bias. By speeding up slow elements and slowing down fast elements, compensation for the relative speed characteristics may be provided.