We present the design (hardware + software) of “Peta-pico-Voltron”, a low-current high voltage power supply for electrostatic actuators. Developed primarily for dielectric elastomer actuators, it offers a low-cost solution to generate user controllable voltages up to 5 kV, either continuous, or as square waves with a frequency range between 1 mHz and 1 kHz. The high voltage power supply was developed as an answer to the lack of commercial devices that combine a low cost (<450 USD), portability, and the ability to generate square signals with a high slew rate (>15 V/µs for a 1 pF load). The PCB is designed to be easy to assemble, with a minimum of panel-mounted elements: the unit is controlled from a computer with a user-friendly interface. A Python library of functions is provided, which enables seamless integration of the power supply with other instruments. Alternatively, simple commands can be sent via a serial connection, which makes it possible to control the power supply with any programming language. The PCB footprint with the soldered components is 120 × 55 × 25 mm3 with a weight of 60 g, thus making it a very compact and portable power supply. We also present a battery management circuit to make the system completely standalone when combined with a Raspberry Pi, a touch screen, and a battery.