Bladder cancer is one of the most commonly diagnosed malignant tumors in the urinary system and causes a massive cancer-related death. DEPDC1B is a DEP domain-containing protein that has been found to be associated with a variety of human cancers. This study aimed to explore the role and mechanism of DEPDC1B in the development of bladder cancer. The analysis of clinical specimens revealed the upregulated expression of DEPDC1B in bladder cancer, which was positively related to tumor grade. In vitro and in vivo studies showed that DEPDC1B knockdown could inhibit the growth of bladder cancer cells or xenografts in mice. The suppression of bladder cancer by DEPDC1B was executed through inhibiting cell proliferation, cell migration, and promoting cell apoptosis. Moreover, a mechanistic study found that SHC1 may be an important route through which DEPDC1B regulates the development of bladder cancer. Knockdown of SHC1 in DEPDC1B-overexpressed cancer cells could abolish the promotion effects induced by DEPDC1B. In conclusion, DEPDC1B was identified as a key regulator in the development of bladder cancer, which may be used as a potential therapeutic target in the treatment of bladder cancer.