Nuclear targeting probes and nanocarriers remain limited in the literature, highlighting a critical gap in subcellular targeting strategies. This review outlines four key strategies for delivering probes and drugs to the cell nucleus. Active targeting with peptides, aptamers, and proteins enables precise nuclear import and supports real-time mapping of epigenetic activity. Cationic molecules bind DNA via charge-based and structural compatibility, while nanoparticle size is tuned to bypass nuclear pores after tumor accumulation. Nuclease-resistant, peptide-conjugated, and light-responsive carriers improve nuclear delivery by avoiding degradation and lysosomal trapping. Lipid-based and aptamer-guided systems bring therapeutics close to genomic DNA, with stimuli like acidity or light enabling controlled release. Carbon and gold nanostructures showcase how these strategies improve nuclear access and therapeutic impact. Overall, effective designs align delivery methods with biological barriers and quantify nuclear targeting efficiency, advancing nucleus-focused diagnostics and treatments.