Compositions including an antibody single-chain variable fragment (scFv) conjugate that specifically binds to ROR1 tumor-associated antigen are provided. The anti-ROR1 scFv antibody and conjugates may include a biologically-active molecule. Such conjugates may comprise a chimeric receptor to direct T cells to respond to ROR1 cancer cells, Methods to use the scFV conjugates to target cells expressing ROR1 for therapeutic and diagnostic purposes are also provided.