| National Background Investigations Bureau | |
| Seal: | NBIB_seal.jpg |
| Preceding1: | Federal Investigative Services Division |
| Superseding1: | Defense Counterintelligence and Security Agency |
| Jurisdiction: | U.S. federal government |
| Headquarters: | Washington, D.C. |
| Region Code: | US |
| Chief1 Name: | Charles S. Phalen |
| Chief1 Position: | Director |
| Parent Department: | United States Office of Personnel Management |
The National Background Investigations Bureau (NBIB) was a semi-autonomous U.S. Government agency that was housed within the United States Office of Personnel Management. In September 2019, background investigations were transferred from OPM's NBIB to Defense Counterintelligence and Security Agency.