Experimental investigations of neutrinos and dark matter are powerful tools to answer the outstanding questions of particle physics in the coming years, such as how neutrinos acquire mass, why we live in a matter-dominated Universe, and what the nature of dark matter is. Searches for neutrinoless double-beta decay (0νββ) and direct detection of Weakly Interacting Massive Particles (WIMPs) have made impressive strides over the past decade to address these critical questions. 0νββ searches provide an exclusive probe into the Majorana nature of neutrinos through a lepton-number-violating process, and offer insights into neutrino mass hierarchy, scale, and mechanism. Observation of 0νββ also supports theories that leptons catalyzed the matter-antimatter asymmetry observed in our Universe. On the other hand, direct detection of WIMPs would confirm the existence and particle nature of dark matter. In this talk, I will present the results and ongoing efforts in the CUORE and COSINE experiments to search for 0νββ and WIMP direct detection, respectively. I will also discuss the prospects of CUPID, the next generation experiment of CUORE.