TGA (TGACG motif-binding factor) proteins are plant-specific group D basic leucine zipper (bZIP) transcription factors that bind as-1/TGACG elements. TGA proteins regulate salicylic acid (SA)-dependent transcription and have context-dependent roles in jasmonic acid (JA)-related defense, growth, development and stress responses. Tea (Camellia sinensis) and oil tea (Camellia oleifera) are Theaceae crops grown for beverages and edible oil, and anthracnose, drought and chilling reduce their yield and quality. Although tea bZIP genes, including group D TGA members, have been cataloged, a comparative, family-wide analysis of TGA genes across representative Theaceae genomes and their cultivar-dependent responses to anthracnose has not been reported. We therefore identified TGA genes genome-wide in six representative Theaceae species: Camellia chekiangoleosa, C. oleifera, C. sinensis, Camellia crapnelliana, Camellia japonica and Stewartia sinensis. Arabidopsis thaliana was included as a reference species. We then examined their phylogeny, gene structure and conserved motifs, codon usage, duplication and collinearity, and promoter cis-elements. Public expression data for 32 TGA genes from C. sinensis, C. oleifera and C. chekiangoleosa were analyzed across tissues and under salt, drought and cold treatments, and a pericarp transcriptome dataset from the resistant ‘MY53’ and susceptible ‘MY01’ C. oleifera genotypes was reanalyzed after inoculation with Colletotrichum fructicola. The survey identified 68 non-redundant TGA genes (10–13 per species), each with intact bZIP and DOG1 domains and predicted nuclear localization. Phylogenetic analysis resolved five groups, and Theaceae members clustered mainly in Groups II and IV, where motif composition and exon–intron structure were conserved. Codon usage bias was weak (effective number of codons: 52–54; codon adaptation index: 0.77–0.80). For 27 within-species paralogous TGA pairs, Ka/Ks distributions remained below 1 (range of 0.046–0.429), and no pair exceeded the Ks > 2 saturation criterion, indicating purifying selection. In the current duplication classification, 6–11 of the 10–13 TGA genes per species were assigned to WGD- or segmental-duplication classes, but family sizes remained similar to A. thaliana (10 genes); the data therefore do not indicate substantial net family expansion. Promoters were enriched in cis-elements responsive to light, JA, SA and abscisic acid (ABA). Expression varied between tissues, and several genes were enriched in fruit and leaves. Salt, drought and cold each induced a subset of TGA genes. The 12 ColeTGA genes resolved into four cultivar-dependent expression patterns; ColeTGA3 and ColeTGA2 showed stronger increases in the resistant ‘MY53’ genotype, whereas ColeTGA7 increased in both genotypes. Together, these comparisons clarify how TGA genes have been conserved and how they diverged among the six sampled Theaceae species.