To ensure high cell viability and genomic stability, cells have evolved two major mechanisms to deal with the constant challenge of DNA replication fork arrest during S phase of the cell cycle: (1) induction of the ataxia telangiectasia and Rad3-related (ATR) replication checkpoint mechanism, and (2) activation of a pathway that bypasses DNA damage and DNA with abnormal structure and is mediated by translesion synthesis (TLS) Y-family DNA polymerases. This review focuses on how DNA polymerase kappa (Pol κ), one of the most highly conserved TLS DNA polymerases, is involved in each of these pathways and thereby coordinates them to choreograph the response to a stalled replication fork. We also describe how loss of Pol κ regulation, which occurs frequently in human cancers, affects genomic stability and contributes to cancer development.