Genome editing has revolutionized plant science, providing an unprecedented ability to precisely manipulate plant genomes. For this study, genome editing was utilized to target and modify the NF-YA8 transcription factor (TF) in tomato plants ( L. var. Heinz 1706). The primary objective of this research was to introduce targeted mutations in a non-transgenic manner to the gene, which encodes the alpha subunit of the Nuclear Factor-Y (NF-Y) heterotrimeric TF, and explore its potential for developing new and improved tomato varieties. Through the transient expression of custom-engineered zinc finger nucleases (ZFNs) in tomato seeds, mutations were successfully introduced in the target gene. The recovered mutant coding sequences showed a significant level of similarity to the wild type, with a range of 86.9% to 98.21%. Genotyping M2 lines revealed monogenic mutations at or near the intended target site. Phenotypic changes were also evident in both vegetative and reproductive stages of plants. The research revealed that NF-YA8 functions as a high-level regulator, orchestrating a developmental cascade that influences key agronomic traits throughout the plant's life cycle, including cotyledon development, stem architecture, inflorescence architecture, flowering time, and fruit size and shape.