Nishiibaraki (西茨城郡, Nishiibaraki-gun), literally West Ibaraki, was a district located in Ibaraki Prefecture, Japan.
As of 2004, the district had an estimated population of 52,291. The total area was 108.64 km2.
There were two municipalities before the dissolution:
On March 19, 2006, the towns of Iwama and Tomobe were merged into the expanded city of Kasama. Therefore, Nishiibaraki District was dissolved as a result of this merger.