A semiconductor package including a thermally conductive bridge and a method of forming are provided. The semiconductor package may include a first semiconductor device having a first substrate and first contact pads on the first substrate, a first thermally conductive feature on the first substrate and extending into the first substrate, a second semiconductor device over the first substrate, wherein the second semiconductor device may include second contact pads electrically connected to the first contact pads, a first thermally conductive bridge over the first semiconductor device and beside the second semiconductor device, and a first encapsulant over the first semiconductor device and along sidewalls of the second semiconductor device and the first thermally conductive bridge. The first thermally conductive bridge may include a second substrate and a second thermally conductive feature on the second substrate and extending into the second substrate, wherein the second thermally conductive feature may be bonded to the first thermally conductive feature.