diff --git a/share/completions/busctl.fish b/share/completions/busctl.fish
new file mode 100644
index 000000000..adb3cf818
--- /dev/null
+++ b/share/completions/busctl.fish
@@ -0,0 +1,186 @@
+# Fish completions for systemd's "busctl" dbus tool
+
+# A ton of functions, all working by the same principle
+# __fish_busctl_*: Get the available options for * via busctl "list" or "introspect"
+# __fish_busctl_has_*: Return 0 when a * is specified (and echo it), else return 1
+# Unfortunately these become a bit slow as they stack because we don't keep state
+# i.e. __fish_busctl_methods needs to know the interface, which needs the object, which needs the busname
+# To speed this up, we'd need to either keep state or just assume e.g. the first non-option argument to "call" is a busname
+
+function __fish_busctl_busnames
+    if __fish_contains_opt user
+		set -l mode "--user"
+	else
+		set -l mode "--system"
+	end
+    command busctl $mode list --no-legend --no-pager ^/dev/null | while read a b; echo $a; end
+end
+
+function __fish_busctl_has_busname
+	for busname in (__fish_busctl_busnames)
+		if contains -- $busname (commandline -opc)
+		   echo $busname
+		   return 0
+		end
+	end
+	return 1
+end
+
+function __fish_busctl_has_object
+	for object in (__fish_busctl_objects)
+		if contains -- $object (commandline -opc)
+		   echo $object
+		   return 0
+		end
+	end
+	return 1
+end
+
+function __fish_busctl_has_interface
+	for interface in (__fish_busctl_interfaces)
+		if contains -- $interface (commandline -opc)
+		   echo $interface
+		   return 0
+		end
+	end
+	return 1
+end
+
+function __fish_busctl_has_member
+	for member in (__fish_busctl_members $argv)
+		if contains -- $member (commandline -opc)
+		   echo $member
+		   return 0
+		end
+	end
+	return 1
+end
+
+function __fish_busctl_has_method
+	__fish_busctl_has_member method
+end
+		 
+function __fish_busctl_has_property
+	__fish_busctl_has_member property
+end
+
+function __fish_busctl_has_signature
+	for signature in (__fish_busctl_signature)
+		if contains -- $signature (commandline -opc)
+		   echo $signature
+		   return 0
+		end
+	end
+	return 1
+end
+
+function __fish_busctl_objects
+    if __fish_contains_opt user
+		set -l mode "--user"
+	else
+		set -l mode "--system"
+	end
+	set -l busname (__fish_busctl_has_busname)
+    command busctl $mode tree --list --no-legend --no-pager $busname ^/dev/null | while read a b; echo $a; end
+end
+
+function __fish_busctl_interfaces
+    if __fish_contains_opt user
+		set -l mode "--user"
+	else
+		set -l mode "--system"
+	end
+	set -l busname (__fish_busctl_has_busname)
+	set -l object (__fish_busctl_has_object)
+    command busctl $mode introspect --list --no-legend --no-pager $busname $object ^/dev/null | while read a b; echo $a; end
+end
+	
+function __fish_busctl_members
+    if __fish_contains_opt user
+		set -l mode "--user"
+	else
+		set -l mode "--system"
+	end
+	set -l busname (__fish_busctl_has_busname)
+	set -l object  (__fish_busctl_has_object)
+	set -l interface (__fish_busctl_has_interface)
+	command busctl $mode introspect --list --no-legend --no-pager $busname $object $interface ^/dev/null | grep "$argv" | while read a b; echo $a; end | sed -e "s/^\.//"
+end
+
+function __fish_busctl_methods
+	__fish_busctl_members method
+end
+
+function __fish_busctl_properties
+	__fish_busctl_members property
+end
+
+function __fish_busctl_signals
+	__fish_busctl_members signal
+end
+
+function __fish_busctl_signature
+    if __fish_contains_opt user
+		set -l mode "--user"
+	else
+		set -l mode "--system"
+	end
+	set -l busname (__fish_busctl_has_busname)
+	set -l object  (__fish_busctl_has_object)
+	set -l interface (__fish_busctl_has_interface)
+	set -l member (__fish_busctl_has_member)
+	command busctl $mode introspect --list --no-legend --no-pager $busname $object $interface ^/dev/null | grep "^.$member " | while read a b c d; echo $c; end
+end
+
+### Commands
+set -l commands list status monitor capture tree introspect call get-property set-property help
+
+complete -f -e -c busctl
+complete -A -f -c busctl -n "not __fish_seen_subcommand_from $commands" -a "$commands"
+
+### Arguments to commands
+# "status" only takes a single service as argument
+complete -f -c busctl -n "__fish_seen_subcommand_from status; and not __fish_busctl_has_busname" -a "(__fish_busctl_busnames)"
+
+# These take multiple services
+complete -f -c busctl -n "__fish_seen_subcommand_from monitor capture tree" -a "(__fish_busctl_busnames)"
+
+# These take "service object interface" (and then maybe something else)
+set -l service_object_interface_commands introspect call get-property set-property
+complete -f -c busctl -n "__fish_seen_subcommand_from $service_object_interface_commands; and not __fish_busctl_has_busname" -a "(__fish_busctl_busnames)"
+complete -f -c busctl -n "__fish_seen_subcommand_from $service_object_interface_commands; and __fish_busctl_has_busname; and not __fish_busctl_has_object" -a "(__fish_busctl_objects)"
+# Having an object implies having a busname, so we only need to check has_object; and not has_interface
+complete -f -c busctl -n "__fish_seen_subcommand_from $service_object_interface_commands; and __fish_busctl_has_object; and not __fish_busctl_has_interface" -a "(__fish_busctl_interfaces)"
+
+# Call takes service object interface method signature arguments
+# We can't complete the arguments (or we'd need to parse the signature)
+complete -f -c busctl -n "__fish_seen_subcommand_from call; and __fish_busctl_has_interface; and not __fish_busctl_has_method" -a "(__fish_busctl_methods)"
+complete -f -c busctl -n "__fish_seen_subcommand_from call; and __fish_busctl_has_method; and not __fish_busctl_has_signature" -a "(__fish_busctl_signature)"
+
+complete -f -c busctl -n "__fish_seen_subcommand_from get-property; and __fish_busctl_has_interface" -a "(__fish_busctl_properties)"
+complete -f -c busctl -n "__fish_seen_subcommand_from set-property; and __fish_busctl_has_interface; and not __fish_busctl_has_property" -a "(__fish_busctl_properties)"
+complete -f -c busctl -n "__fish_seen_subcommand_from set-property; and __fish_busctl_has_property; and not __fish_busctl_has_signature" -a "(__fish_busctl_signature)"
+
+
+# Flags
+# These are incomplete as I have no idea how to complete --address= or --match=
+complete -f -c busctl -n "__fish_seen_subcommand_from call get-property" -l quiet
+complete -f -c busctl -n "__fish_seen_subcommand_from call get-property" -l verbose
+complete -f -c busctl -n "__fish_seen_subcommand_from tree introspect" -l list
+complete -f -c busctl -n "__fish_seen_subcommand_from call" -l expect-reply= -a "yes no"
+complete -f -c busctl -n "__fish_seen_subcommand_from call" -l auto-start= -a "yes no"
+complete -f -c busctl -n "__fish_seen_subcommand_from call" -l allow-interactive-authorization= -a "yes no"
+complete -f -c busctl -n "__fish_seen_subcommand_from call" -l timeout= -a "(seq 0 100)"
+complete -f -c busctl -n "__fish_seen_subcommand_from list" -l unique
+complete -f -c busctl -n "__fish_seen_subcommand_from list" -l acquired
+complete -f -c busctl -n "__fish_seen_subcommand_from list" -l activatable
+complete -f -c busctl -n "__fish_seen_subcommand_from list" -l show-machine
+complete -f -c busctl -n "__fish_seen_subcommand_from list status" -l augment-creds= -a "yes no"
+complete -f -c busctl -l user
+complete -f -c busctl -l system
+complete -f -c busctl -s H -l host= -a "(__fish_print_hostnames)"
+complete -f -c busctl -s M -l machine= -a "(machinectl list --no-legend --no-pager)"
+complete -f -c busctl -l no-pager
+complete -f -c busctl -l no-legend
+complete -f -c busctl -s h -l help
+complete -f -c busctl -l version