Objective Although expression of the TEAD1 protein in preadipocytes has been established, its function remains unclear. In this study, we sought to detect transcripts of TEAD1 in chicken and to examine the effects of this protein on the proliferation, migration, apoptosis, and differentiation of immortalized chicken preadipocyte cell lines (ICP1).Methods The full-length sequence of the TEAD1 gene was cloned and the two transcripts were subjected to bioinformatics analysis. The subcellsular localization of TEAD1 transcripts was determined based on indirect immunofluorescence. The effects of TEAD1 transcripts overexpression on the proliferation of ICP1 cells were examined by RT-qPCR, CCK-8, and EdU assays; the effects of TEAD1 transcripts on ICP1 cells migration were examined based on the scratch test; and the effects of TEAD1 transcripts overexpression on ICP1 cells apoptosis were analyzed using apoptosis-Hoechst staining and RT-qPCR. The expression of TEAD1 transcripts in different tissues, cells lines, and ICP1 at different periods of differentiation was analyzed by RT-qPCR. The effects of TEAD1 transcripts overexpression on lipid droplet accumulation and adipogenic-related gene expression in ICP1 cells were analyzed based on Oil Red O and BODIPY staining, RT-qPCR, Western blot, and dual-luciferase reporter gene assays. Finally, the content of triglyceride (TG) was measured in TEAD1 overexpressed ICP1 cells.Results The full-length TEAD1 was cloned and two TEAD1 transcripts were identified. The TEAD1-V1 protein was found to be localized primarily in the cell nucleus, whereas the TEAD1-V2 protein is localized in the cell cytoplasm and nucleus. The overexpression of both TEAD1-V1 and TEAD1-V2 significantly inhibited the proliferation of ICP1 cells. Whereas the overexpression of TEAD1-V1 promoted ICP1 cell migration, the overexpression of TEAD1-V2 had no significant effects on ICP1 migration; the overexpression of both TEAD1-V1 and TEAD1-V2 significantly promoted the apoptosis of ICP1 cells. We found that the different transcripts of TEAD1 have similar expression pattern in different tissues and cells lines. During induced preadipocyte differentiation, the expression of these genes initially declined, although subsequently increased. Overexpression of TEAD1-V1 promoted a significant reduction in lipid droplet formation and inhibited C/EBPα expression during the differentiation of ICP1 cells (P<0.05). However, the overexpression of TEAD1-V2 had no significant effect on lipid droplet accumulation or the expression of adipogenic-related proteins (P>0.05). Overexpression of TEAD1-V1 significantly decreased triglyceride content in ICP1 cells (P<0.05), while overexpression of TEAD1-V2 had no effect on triglyceride content in ICP1 cells (P>0.05).Conclusion In this study, for the first time, identified two TEAD1 transcripts. Overexpressed transcripts TEAD1-V1 and TEAD1-V2 both inhibited the proliferation of chicken preadipocytes and promoted apoptosis of chicken preadipocytes. TEAD1-V1 inhibited the differentiation of preadipocytes and promoted the migration of preadipocytes, while TEAD1-V2 had no effect on the differentiation and migration of preadipocytes.