Background: Tertiary lymphoid structures (TLSs) are spatial immune niches in solid tumors, but their relationship to mature regulatory dendritic-cell (mregDC) states in ovarian cancer remains incompletely resolved. Methods: We integrated public gynecological-tumor single-cell RNA sequencing, representative CD11C/HLA-DRA/LAMP3/CCR7 multiplex immunofluorescence, public Xenium and multi-sample spatial transcriptomics, TCGA-OV immune deconvolution and exploratory prognostic modeling, scTenifoldKnk and CellOracle perturbation analyses, and supplementary computational drug prioritization. Results: A $LAMP{3}^{+}CCR{7}^{+}$ dendritic-cell state showed mature migratory, antigen-presentation, checkpoint, and NF-$\kappa$B/TNF-associated programs. Spatial analyses linked TLS-score-defined regions to mregDC, antigen-presentation/MHC-II proxy, and interferon-associated signals, with distance-gradient analyses supporting TLS-proximal enrichment. Immune deconvolution associated the TLS/mregDC axis with an immune-infiltrated TCGA-OV contexture, whereas adjusted analyses emphasized dependence on broader immune-program richness. Perturbation analyses nominated candidate regulatory axes for experimental testing, and the supplementary drug-prioritization layer was retained only as target-class hypothesis support. Conclusions: These data support a hypothesis-generating model of a TLS-associated $LAMP{3}^{+}CCR{7}^{+}$ mregDC antigen-presentation program in ovarian cancer, while requiring raw-channel tissue validation, functional perturbation, and independent clinical testing.