quantum-mechanical particles constrained to a curved wire were found to be affected by the geometrical curvature and torsion, which are encoded in the quantum geometrical scalar [1,2] and vector [3,4] potentials. They cause a vast of intriguing phenomena at the nanoscale including topological band structure of electrons bound to periodic minimal surfaces, [5] winding-generated bound states in spirally rolled-up nanotubes, [6] torsion generated confinement of electron by the spin-orbit coupling in a nanoscale helical wire, [3] with some of these effects resulting in a chiral symmetry breaking. [3] Much attention is dedicated also to superconductivity in curved geometries. [7][8][9] Especially for chiral superconductors, where the physical implications of the geometric curvature results in the geometric Josephson effects, geometry-based superconducting quantum interference devices and radiators. [10] Curvilinear and 3D mesoscale systems are actively explored in other disciplines including quantum systems, [3,11] semiconductors (not only fundamental research but also current transistor technologies), [12][13][14] Dirac materials, [15,16] photonics, [17][18][19] and plasmonics [20][21][22] for intra-chip multilevel communication [23] as well as in liquid crystals, [24][25][26] microrobotics, [27][28][29] and magnetism. [30] Curvilinear magnetism encompasses a range of effects of geometrical curvature on magnetic responses of low-dimensional Low-dimensional magnetic architectures including wires and thin films are key enablers of prospective ultrafast and energy efficient memory, logic, and sensor devices relying on spin-orbitronic and magnonic concepts. Curvilinear magnetism emerged as a novel approach in material science, which allows tailoring of the fundamental anisotropic and chiral responses relying on the geometrical curvature of magnetic architectures. Much attention is dedicated to magnetic wires of Möbius, helical, or DNA-like double helical shapes, which act as prototypical objects for the exploration of the fundamentals of curvilinear magnetism. Although there is a bulk number of original publications covering fabrication, characterization, and theory of magnetic wires, there is no comprehensive review of the theoretical framework of how to describe these architectures. Here, theoretical activities on the topic of curvilinear magnetic wires and narrow nanoribbons are summarized, providing a systematic review of the emergent interactions and novel physical effects caused by the curvature. Prospective research directions of curvilinear spintronics and spin-orbitronics are discussed, the fundamental framework for curvilinear magnonics are outlined, and mechanically flexible curvilinear architectures for soft robotics are introduced.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202105219.