Gastric cancer (GC) is one of the most common types of cancer. Earlier research has suggested an association of microfibril-associated protein 5 (MFAP5) and collagen type I alpha 1 (COL1A1) with the progression of various tumors. However, the specific roles and mechanisms of action of MFAP5 and COL1A1 in the context of GC are yet to be fully elucidated. Thus, the objective of this study is to investigate the functions of MFAP5 and COL1A1 in the epithelial-mesenchymal transition (EMT) of GC and to unravel the associated molecular mechanisms. We examined the MFAP5 expression level in GC through real-time polymerase chain reaction (RT-PCR), western blotting, and immunohistochemistry. Subsequently, shRNA interference was employed to knockdown the expression of MFAP5 or COL1A1 in GC cells. Cell viability assay, Transwell assay, RT-PCR, and western blotting were then used to explore the impact of MFAP5 and COL1A1 on GC progression and metastasis, along with GC cell proliferation, migration, and EMT. Increased MFAP5 levels were observed in both GC tissues and cells (p < 0.05), with decreased MFAP5 levels significantly impeding GC cell activity and GC progression and metastasis (p < 0.05). Additionally, the pronounced reduction in the COL1A1 expression level effectively alleviated the migration and EMT processes induced by MFAP5 overexpression in GC cells (p < 0.05). These results indicate that MFAP5 plays a role in initiating the process of EMT in GC cells through the upregulation of COL1A1 expression.