  Minicharged particles (mCPs), hypothetical free particles with tiny electric
charges below the elementary charge, $e$, offer a valuable probe of dark
sectors and fundamental physics through several clear experimental signatures.
Various models of physics beyond the Standard Model predict the existence of
such particles, which could help elucidate the ongoing mysteries regarding
electric charge quantization and the nature of dark matter. Moreover, a
hypothetical scenario involving a small minicharged subcomponent of dark matter
has recently been demonstrated as a viable explanation of the anomaly in the 21
cm hydrogen absorption signal reported by the EDGES collaboration. Although
several decades of indirect observations and direct experimental searches for
mCPs at particle accelerators have led to severe constraints, a substantial
window of the mCP mass$\unicode{x2013}$mixing parameter space remains
unexplored at the energy frontier accessible to current state-of-the-art
accelerators, such as the Large Hadron Collider (LHC). Consequently, mCPs have
remained topical over the years, and new experimental searches at accelerators
have been gaining interest. In this article, we review the theoretical
frameworks in which mCPs emerge and their phenomenological implications, the
current direct and indirect constraints on mCPs, and the present state of the
ongoing and upcoming searches for mCPs at particle accelerators. Additionally,
we present the results of an updated study of the projected sensitivity of the
recently approved (and relocated) Phase-1 detector of the MoEDAL's Apparatus
for Penetrating Particles (MAPP) experiment to Drell$\unicode{x2013}$Yan
pair-produced mCPs at the LHC's Run 3 and the future High-Luminosity LHC.
