Junction-isolated blocking voltage devices and methods of forming the same are provided. In certain implementations, a blocking voltage device includes an anode terminal electrically connected to a first p-well, a cathode terminal electrically connected to a first n-well, a ground terminal electrically connected to a second p-well, and an n-type isolation layer for isolating the first p-well from a p-type substrate. The first p-well and the first n-well operate as a blocking diode. The blocking voltage device further includes a PNPN silicon controlled rectifier (SCR) associated with a P+ region formed in the first n-well, the first n-well, the first p-well, and an N+ region formed in the first p-well. Additionally, the blocking voltage device further includes an NPNPN bidirectional SCR associated with an N+ region formed in the first p-well, the first p-well, the n-type isolation layer, the second p-well, and an N+ region formed in the second p-well.