Their chemical stability, high specific surface area, and electric conductivity enable porous carbon materials to be the most commonly used electrode materials for electrochemical capacitors (also known as supercapacitors). To further increase the energy and power density, engineering of the pore structures with a higher electrochemical accessible surface area, faster ion‐transport path and a more‐robust interface with the electrolyte is widely investigated. Compared with traditional porous carbons, two‐dimensional (2D) porous carbon sheets with an interlinked hierarchical porous structure are a good candidate for supercapacitors due to their advantages in high aspect ratio for electrode packing and electron transport, hierarchical pore structures for ion transport, and short ion‐transport length. Recent progress on the synthesis of 2D porous carbons is reported here, along with the improved electrochemical behavior due to enhanced ion transport. Challenges for the controlled preparation of 2D porous carbons with desired properties are also discussed; these require precise tuning of the hierarchical structure and a clarification of the formation mechanisms. Two‐dimensional (2D) porous carbon sheets, which can be synthesized by templating approaches, biomass carbonization, biomass carbonization–activation, in situ activation, etc, are good candidates for supercapacitors due to their advantages in their short ion‐transport length and high aspect ratio for electrode packing and electron transport.