Hepatitis B virus (HBV) is a devastating human pathogen with upwards of 250 million people chronically infected. HBV is a leading cause of end-stage liver disease (cirrhosis) and hepatocellular carcinoma. Due to the inability of current treatments to eliminate the HBV reservoir and the frequent occurrence of resistant strains, additional therapies are required. Toward this goal we sought to identify novel host factors required for HBV replication using a whole genome RNAi screen in cells constitutively infected with HBV. This screen identified 69 novel high-confidence candidates which modulate HBV replication. Of these, four were found to be required for viral transcription, BRCA1, SIRT2, YWHAH, and ZCCHC14. Moreover, YWHAH and ZCCHC14 were found to be required for the productive infection in clinical HBV isolates of both transformed cells and primary human hepatocytes. Our siRNA screen discovered several HBV host factors that contribute to productive HBV replication and thus represent potential targets for anti-HBV therapies.