Following activation by cognate antigen, B cells undergo fine-tuning of their antigen receptors and may ultimately differentiate into antibody-secreting cells (ASCs). While antigen-specific B cells that express surface receptors (B cell receptors BCRs) can be readily cloned and sequenced following flow sorting, antigen-specific ASCs that lack surface BCRs cannot be easily profiled. Here, we report an approach, TRAPnSeq (antigen specificity mapping through immunoglobulin Ig secretion TRAP and Sequencing), that allows capture of secreted antibodies on the surface of ASCs, which in turn enables high-throughput screening of single ASCs against large antigen panels. This approach incorporates flow cytometry, standard microfluidic platforms, and DNA-barcoding technologies to characterize antigen-specific ASCs through single-cell V(D)J, RNA, and antigen barcode sequencing. We show the utility of TRAPnSeq by profiling antigen-specific IgG and IgE ASCs from both mice and humans and highlight its capacity to accelerate therapeutic antibody discovery from ASCs. Display omitted •TRAPnSeq allows antigen specificity mapping through Ig secretion TRAP and Sequencing•High-throughput profiling of ASCs based on local antibody capture•TRAPnSeq enables rapid antibody discovery from ASCs and elucidates Ag+ ASC biology Emerging techniques have enabled high-throughput profiling of antigen-specific (Ag+) B cells, which has expanded our understanding of the B cell repertoire. A key limitation of existing platforms is profiling of Ag+ antibody-secreting cells (ASCs) that downregulate their surface BCRs. TRAPnSeq improves on this limitation by incorporating an antibody secretion trap that captures secreted antibodies on the surface of ASCs, which in turn enables rapid and high-throughput profiling of Ag+ ASCs. Asrat et al. develop a method, TRAPnSeq, that enables specific isolation and profiling of antigen-specific (Ag+) antibody-secreting cells. They show the utility of TRAPnSeq in mice and humans by performing high-throughput analysis of Ag+ IgG and IgE plasma cells.