Proteinase-activated receptor-1 (PAR1) protein belongs to the G-protein coupled receptor (GPCR) family. The wide distribution of PAR1 in a variety of cells supports the idea that they are involved in many processes, including coagulation, proliferation and adhesion. Some studies have reported that PAR1 may be involved in cancer initiation and progression. However, the role of PAR1 in bladder cancer (BC) has not yet been clarified. Therefore, in this study, we wished to address the following questions: (1) Does PAR1 act as an oncogene or tumor suppressor in BC? (2) Does PAR1 have an impact on the proliferation, migration and invasion of BC cells? (3) What is the molecular mechanism that PAR1 regulates proliferation, migration and invasion of BC cell lines? To be more specific, which signalling pathways are regulated by PAR1? (4) Does PAR1 influence the functions of BC cells through thrombin activation? PAR1 expression was assessed by RT-qPCR and Western blot in bladder epithelial cell lines (Y235T, HBLAK and UROtsa) and BC cell lines (RT4, T24 and UMUC-3). Stable ectopic PAR1 expression was used to elucidate the role of PAR1 in BC cells (T24 and UMUC-3). MTT assay, Boyden chamber assay, soft agar and scratch assay experiments were used for functional experiments. The real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot results revealed higher PAR1 levels in normal urothelial cells compared to BC cell lines. Similarly, the RT-qPCR results showed reduced PAR1 mRNA levels in N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced mouse BC compared to normal mouse bladder tissue. Importantly, functional experiments indicate a potential tumor suppressor role of PAR1 in bladder tissue. In fact, PAR1 overexpression impaired proliferation, migration and invasion abilities of T24 and UMUC-3 BC cell lines. Furthermore, the results showed that PAR1 regulates AKT and Hippo-Yes-associated protein (YAP) signalling pathways, which suggests that PAR1-mediated effects on cell proliferation, migration, invasion and angiogenesis may involve these pathways, at least in part. Of note, the activation of phosphorylated AKT is partly mediated by the protease thrombin, a main effector of the coagulation pathway, which is known to activate PAR1 by cleavage of an N-terminal region. This study is the first time to demonstrate the potential role of PAR1 in BC and indicates that PAR1 may impair proliferation, migration and invasion of BC cells via AKT and Hippo-YAP signalling pathways. Further studies are needed to reveal the detailed mechanism of PAR1 in BC.