  Particle physics today faces the challenge of explaining the mystery of dark
matter, the origin of matter over anti-matter in the Universe, the origin of
the neutrino masses, the apparent fine-tuning of the electro-weak scale, and
many other aspects of fundamental physics. Perhaps the most striking frontier
to emerge in the search for answers involves new physics at mass scales
comparable to familiar matter, below the GeV-scale, or even radically below,
down to sub-eV scales, and with very feeble interaction strength. New
theoretical ideas to address dark matter and other fundamental questions
predict such feebly interacting particles (FIPs) at these scales, and indeed,
existing data provide numerous hints for such possibility. A vibrant
experimental program to discover such physics is under way, guided by a
systematic theoretical approach firmly grounded on the underlying principles of
the Standard Model. This document represents the report of the FIPs 2022
workshop, held at CERN between the 17 and 21 October 2022 and aims to give an
overview of these efforts, their motivations, and the decadal goals that
animate the community involved in the search for FIPs.
