This lecture explores the coupling of spins to mechanical oscillators in the quantum regime, focusing on the Nitrogen-Vacancy (NV) center in diamond. Topics include the quantization axis, spin-mechanical coupling, and the interaction between spins and mechanics. The presentation delves into experiments involving the NV center, such as mechanically detected magnetic resonance and dipole-dipole enhanced mechanical rotation. The instructor discusses the implications of dipolar interactions, the resonant dipole-dipole enhanced rotation, and the transition from para- to diamagnetism in NV centers. The lecture concludes with insights on spin-diamagnetism and its applications in trapping nanodiamonds under liquid environments.