Clustal is a computer program used for multiple sequence alignment in bioinformatics. The software have gone through several iterations, with ClustalΩ (Omega) being the latest version as of 2011. It is available as standalone software, via a web interface, and through a server hosted by the European Bioinformatics Institute.

Desmond Gerard Higgins is a Professor of Bioinformatics at University College Dublin, widely known for CLUSTAL, a series of computer programs for performing multiple sequence alignment. According to Nature, Higgins' papers describing CLUSTAL are among the top ten most highly cited scientific papers of all time.