Ligamenvirales is an order of linear viruses that infect archaea of the phylum Thermoproteota (formerly Crenarchaeota) and have double-stranded DNA genomes.

[1] The order was proposed by David Prangishvili and Mart Krupovic in 2012 and subsequently created by the International Committee on Taxonomy of Viruses (ICTV).

[3][4] The major coat proteins of both lipothrixviruses and rudiviruses have an unusual four-helix bundle topology.

In both groups of viruses, the major capsid proteins form a claw-like dimer (homodimer in rudiviruses and heterodimer in lipothrixviruses), which wraps around the dsDNA.

[citation needed] Members of the Ligamenvirales are structurally related to archaeal viruses of the family Tristromaviridae which, similar to lipothrixviruses, encode two paralogous major capsid proteins with the same fold as in ligamenviruses.