Abstract: Provided are ROR1 binding molecules, including anti-ROR1 antibodies, including antibody fragments such as variable heavy chain (VH) regions, single-chain fragments, and chimeric receptors including the antibodies, such as chimeric antigen receptors (CARs). In some embodiments, the antibodies specifically bind to ROR1. Among the antibodies are human antibodies, including those that compete for binding to ROR1 with reference antibodies, such as a non-human reference antibody. Also provided are genetically engineered cells expressing the chimeric receptors, and uses of the binding molecules and cells adoptive cell therapy.