Boosted Electrostatic Discharge (ESD) clamp circuit with high effective holding voltage. In some embodiments, an integrated circuit may include a trigger circuit operably coupled to a first voltage bus and to a reference bus; a diode including an anode terminal operably coupled to a second voltage bus, the second voltage bus distinct from the first voltage bus; a transistor including a gate operably coupled to an output terminal of the trigger circuit, a drain operably coupled to a cathode terminal of the diode, and a source operably coupled to the reference bus; and an input/output (I/O) cell operably coupled to the first voltage bus, the second voltage bus, and the reference bus.