GATA1, a member of the GATA transcription factor family, was reported to play a role in development and progression of erythroid cells and breast cancer cells. However, the role of GATA1 in colorectal cancer (CRC) is unknown. Here, we demonstrate that GATA1 was upregulated in CRC tissues compared with normal tissues, and predicted poor clinical outcome in CRC. Biological functional analyses showed that GATA1 knockdown decreased CRC cells proliferation, migration and invasion, and regulated the process of epithelial–mesenchymal transition (EMT). Moreover, silencing of GATA1 suppressed colorectal tumor growth in nude mice. Mechanistically, GATA1 overexpression significantly increased the activity of PI3K/AKT signaling pathway in CRC cells. These data provide insight into the important role of GATA1 in CRC progression and suggest that GATA1 is a potential therapeutic target for CRC.