Formic acid (HCOOH) has emerged as a promising H2 energy carrier due to its reasonable gravimetric and volumetric H2 densities, low toxicity, low flammability, and ease of handling. Its possible productions from biogenic feedstocks also make it an attractive source to produce H2 on demand. The utilization of HCOOH as a liquid H2 carrier requires catalytic systems to selectively dehydrogenate HCOOH at low temperatures without forming CO products that can act as a poison in fuel cell applications. In this review, we summarize the recent progress in understanding HCOOH decomposition via dehydrogenation (to CO2/H2) and dehydration (to CO/H2O) pathways on transition metals, including Cu, Pt, Pd, and Au. The focus is on discussing the surface chemistry of HCOOH reactions on transition metals, including the types of bound intermediates and the identity and kinetic relevance of elementary steps. In doing so, we review current catalyst design strategies for HCOOH dehydrogenation to facilitate the future development of catalytic processes for H2 storage/utilization.