diff --git a/software/muscle/functions.nf b/software/muscle/functions.nf
new file mode 100644
index 00000000..da9da093
--- /dev/null
+++ b/software/muscle/functions.nf
@@ -0,0 +1,68 @@
+//
+//  Utility functions used in nf-core DSL2 module files
+//
+
+//
+// Extract name of software tool from process name using $task.process
+//
+def getSoftwareName(task_process) {
+    return task_process.tokenize(':')[-1].tokenize('_')[0].toLowerCase()
+}
+
+//
+// Function to initialise default values and to generate a Groovy Map of available options for nf-core modules
+//
+def initOptions(Map args) {
+    def Map options = [:]
+    options.args            = args.args ?: ''
+    options.args2           = args.args2 ?: ''
+    options.args3           = args.args3 ?: ''
+    options.publish_by_meta = args.publish_by_meta ?: []
+    options.publish_dir     = args.publish_dir ?: ''
+    options.publish_files   = args.publish_files
+    options.suffix          = args.suffix ?: ''
+    return options
+}
+
+//
+// Tidy up and join elements of a list to return a path string
+//
+def getPathFromList(path_list) {
+    def paths = path_list.findAll { item -> !item?.trim().isEmpty() }      // Remove empty entries
+    paths     = paths.collect { it.trim().replaceAll("^[/]+|[/]+\$", "") } // Trim whitespace and trailing slashes
+    return paths.join('/')
+}
+
+//
+// Function to save/publish module results
+//
+def saveFiles(Map args) {
+    if (!args.filename.endsWith('.version.txt')) {
+        def ioptions  = initOptions(args.options)
+        def path_list = [ ioptions.publish_dir ?: args.publish_dir ]
+        if (ioptions.publish_by_meta) {
+            def key_list = ioptions.publish_by_meta instanceof List ? ioptions.publish_by_meta : args.publish_by_meta
+            for (key in key_list) {
+                if (args.meta && key instanceof String) {
+                    def path = key
+                    if (args.meta.containsKey(key)) {
+                        path = args.meta[key] instanceof Boolean ? "${key}_${args.meta[key]}".toString() : args.meta[key]
+                    }
+                    path = path instanceof String ? path : ''
+                    path_list.add(path)
+                }
+            }
+        }
+        if (ioptions.publish_files instanceof Map) {
+            for (ext in ioptions.publish_files) {
+                if (args.filename.endsWith(ext.key)) {
+                    def ext_list = path_list.collect()
+                    ext_list.add(ext.value)
+                    return "${getPathFromList(ext_list)}/$args.filename"
+                }
+            }
+        } else if (ioptions.publish_files == null) {
+            return "${getPathFromList(path_list)}/$args.filename"
+        }
+    }
+}
diff --git a/software/muscle/main.nf b/software/muscle/main.nf
new file mode 100644
index 00000000..9f4747a4
--- /dev/null
+++ b/software/muscle/main.nf
@@ -0,0 +1,60 @@
+// Import generic module functions
+include { initOptions; saveFiles; getSoftwareName } from './functions'
+
+params.options = [:]
+options        = initOptions(params.options)
+
+process MUSCLE {
+    tag "$meta.id"
+    label 'process_medium'
+    publishDir "${params.outdir}",
+        mode: params.publish_dir_mode,
+        saveAs: { filename -> saveFiles(filename:filename, options:params.options, publish_dir:getSoftwareName(task.process), meta:meta, publish_by_meta:['id']) }
+
+    conda (params.enable_conda ? "bioconda::muscle=3.8.1551" : null)
+    if (workflow.containerEngine == 'singularity' && !params.singularity_pull_docker_container) {
+        container "https://depot.galaxyproject.org/singularity/muscle:3.8.1551--h7d875b9_6"
+    } else {
+        container "quay.io/biocontainers/muscle:3.8.1551--h7d875b9_6"
+    }
+
+    input:
+    tuple val(meta), path(fasta)
+
+    output:
+    tuple val(meta), path("*.afa") , optional: true, emit: aligned_fasta
+    tuple val(meta), path("*.phyi"), optional: true, emit: phyi
+    tuple val(meta), path("*.phys"), optional: true, emit: phys
+    tuple val(meta), path("*.clw") , optional: true, emit: clustalw
+    tuple val(meta), path("*.html"), optional: true, emit: html
+    tuple val(meta), path("*.msf") , optional: true, emit: msf
+    tuple val(meta), path("*.tree"), optional: true, emit: tree
+    path "*.log"                                   , emit: log
+    path "*.version.txt"                           , emit: version
+
+    script:
+    def software    = getSoftwareName(task.process)
+    def prefix   = options.suffix ? "${meta.id}${options.suffix}" : "${meta.id}"
+    def fasta_out   = options.args.contains('-fasta') ? "-fastaout ${prefix}_muscle_msa.afa" : ''
+    def clw_out     = options.args.contains('-clw') ? "-clwout ${prefix}_muscle_msa.clw" : ''
+    def msf_out     = options.args.contains('-msf') ? "-msfout ${prefix}_muscle_msa.msf" : ''
+    def phys_out    = options.args.contains('-phys') ? "-physout ${prefix}_muscle_msa.phys" : ''
+    def phyi_out    = options.args.contains('-phyi') ? "-phyiout ${prefix}_muscle_msa.phyi" : ''
+    def html_out    = options.args.contains('-html') ? "-htmlout ${prefix}_muscle_msa.html" : ''
+    def tree_out    = options.args.contains('-maketree') ? "-out ${prefix}_muscle_msa.tree" : ''
+
+    """
+    muscle \\
+        $options.args \\
+        -in $fasta \\
+        $fasta_out \\
+        $clw_out \\
+        $msf_out \\
+        $phys_out \\
+        $phyi_out \\
+        $html_out \\
+        $tree_out \\
+        -loga muscle_msa.log
+    muscle -version |  sed 's/^MUSCLE v//; s/by.*\$//' > ${software}.version.txt
+    """
+}
diff --git a/software/muscle/meta.yml b/software/muscle/meta.yml
new file mode 100644
index 00000000..e0eb5289
--- /dev/null
+++ b/software/muscle/meta.yml
@@ -0,0 +1,56 @@
+name: muscle
+description: MUSCLE is a program for creating multiple alignments of amino acid or nucleotide sequences. A range of options are provided that give you the choice of optimizing accuracy, speed, or some compromise between the two
+keywords:
+    - msa
+    - multiple sequence alignment
+tools:
+  - muscle:
+      description: MUSCLE is a multiple sequence alignment tool with high accuracy and throughput
+      homepage: https://www.drive5.com/muscle
+      documentation: http://www.drive5.com/muscle/muscle.html#_Toc81224840
+      doi: "https://pubmed.ncbi.nlm.nih.gov/15034147/"
+      licence: ['http://www.drive5.com/muscle/manual/license.html']
+input:
+  - fasta:
+      type: file
+      description: Input sequences for alignment must be in FASTA format
+      pattern: "*.{fasta,fa,fna}"
+output:
+  - aligned_fasta:
+      type: file
+      description: Multiple sequence alignment produced in FASTA format
+      pattern: "*.{afa}"
+  - msf:
+      type: file
+      description: GCG Multiple Sequence File (MSF) alignment format (similar to CLUSTALW)
+      pattern: "*.{msf}"
+  - clustalw:
+      type: file
+      description: Multiple sequence alignment produced in ClustalW format without base/residue numbering
+      pattern: "*.{clw}"
+  - phyi:
+      type: file
+      description: Multiple sequence alignment produced in PHYLIP interleaved format
+      pattern: "*.{phyi}"
+  - phys:
+      type: file
+      description: Multiple sequence alignment produced in PHYLIP sequential format
+      pattern: "*.{phys}"
+  - html:
+      type: file
+      description: Multiple sequence alignment produced in HTML format
+      pattern: "*.{html}"
+  - tree:
+      type: file
+      description: NJ or UPGMA tree in Newick format produced from a multiple sequence alignment
+      pattern: "*.{tree}"
+  - log:
+      type: file
+      description: Log file of MUSCLE run
+      pattern: "*{.log}"
+  - version:
+      type: file
+      description: File containing MUSCLE software version
+      pattern: "*.{version.txt}"
+authors:
+  - "@MGordon"
diff --git a/tests/config/pytest_software.yml b/tests/config/pytest_software.yml
index 2ec0478c..c1edd426 100644
--- a/tests/config/pytest_software.yml
+++ b/tests/config/pytest_software.yml
@@ -463,6 +463,10 @@ multiqc:
   - software/multiqc/**
   - tests/software/multiqc/**
 
+muscle:
+  - software/muscle/**
+  - tests/software/muscle/**
+
 nanolyse:
   - software/nanolyse/**
   - tests/software/nanolyse/**
diff --git a/tests/software/muscle/main.nf b/tests/software/muscle/main.nf
new file mode 100644
index 00000000..2119b0fa
--- /dev/null
+++ b/tests/software/muscle/main.nf
@@ -0,0 +1,15 @@
+#!/usr/bin/env nextflow
+
+nextflow.enable.dsl = 2
+
+include { MUSCLE } from '../../../software/muscle/main.nf' addParams( options: ['args': '-fasta -verbose -phys -phyi -maxiters 2'])
+include { MUSCLE as MUSCLE_TREE } from '../../../software/muscle/main.nf' addParams( options: ['args': '-maketree'])
+
+workflow test_muscle {
+
+    input = [ [ id:'test' ], // meta map
+              file(params.test_data['sarscov2']['genome']['informative_sites_fas'], checkIfExists: true) ]
+
+    MUSCLE ( input )
+    MUSCLE_TREE ( MUSCLE.out.aligned_fasta )
+}
diff --git a/tests/software/muscle/test.yml b/tests/software/muscle/test.yml
new file mode 100644
index 00000000..8f7db089
--- /dev/null
+++ b/tests/software/muscle/test.yml
@@ -0,0 +1,14 @@
+- name: muscle test_muscle
+  command: nextflow run tests/software/muscle -entry test_muscle -c tests/config/nextflow.config
+  tags:
+    - muscle
+  files:
+    - path: output/muscle/muscle_msa.log
+    - path: output/muscle/test_muscle_msa.afa
+      md5sum: 93732f6876054d82b0cd252d702c143f
+    - path: output/muscle/test_muscle_msa.phyi
+      md5sum: 1f2a246dcca53125456149770763d5d1
+    - path: output/muscle/test_muscle_msa.phys
+      md5sum: 12f9dd45672a3d92ba1205fcc8010490
+    - path: output/muscle/test_muscle_msa.tree
+      md5sum: 6bf1080bca2440f08ffa2675f74f732a