592705 The disclosure provides 4-amino-4-oxobutanoyl peptides and cyclic analogues thereof of Formula I and the pharmaceutically salts thereof. The variables are defined herein. Certain compounds of Formula I are useful as antiviral agents. 4-amino-4-oxobutanoyl peptide cyclic analogues as disclosed herein are potent and/ or selective inhibitors of viral replication, particularly Hepatitis C virus replication. The disclosure also provides pharmaceutical compositions containing one or more 4-amino-4-oxobutanoyl peptide cyclic analogues and one or more pharmaceutically acceptable carriers. Such pharmaceutical compositions may contain a 4-amino-4-oxobutanoyl peptide cyclic analogue as the only active agent or may contain a combination of a 4-amino-4-oxobutanoyl peptide cyclic analogue and one or more other pharmaceutically active agents. The disclosure also provides methods for treating viral infections, including Hepatitis C infections, in patients.