ADP‐ribosyl transferase member 1 (PARP1) is primarily known for its involvement in signaling DNA damage repair mechanisms within a cell. PARP1 inhibitors are used currently for the management of breast cancer (BRCA) gene mutated breast and ovarian cancers. These current generation PARP1 inhibitors are non‐selective for PARP1, over the PARP superfamily enzymes. Here we report on a novel class of PARP1 inhibitors, the α‐aminophosphonates. α‐Αminophosphonates 1–23 were screened in silico for their binding interactions and tested for inhibitory activity against PARP1. α‐Aminophosphonates 17 and 20 were identified as the most effective PARP1 inhibitors. They inhibited PARP1’s activity, at 10 μM, by 63±3% and 56±3%, respectively.