Apparatus and methods for power amplifiers isolated by differential ground are provided. In certain implementations, a mobile device includes a transceiver that generates a plurality of radio frequency input signals including a first radio frequency input signal and a second radio frequency input signal, and a plurality of differential power amplifiers including a first differential power amplifier that provides amplification to the first radio frequency input signal and a second differential power amplifier that provides amplification to the second radio frequency input signal. The first differential power amplifier and the second differential power amplifier each operate with differential ground so as to provide isolation between the first differential power amplifier and the second differential power amplifier.