diff --git a/client/interfaces.go b/client/interfaces.go
index cc374a9bff81..8ea4b172c239 100644
--- a/client/interfaces.go
+++ b/client/interfaces.go
@@ -426,6 +426,13 @@ type InstanceServer interface {
 	UpdateClusterGroup(name string, group api.ClusterGroupPut, ETag string) error
 	GetClusterGroup(name string) (*api.ClusterGroup, string, error)
 
+	// Site functions ("sites" API extension)
+	GetSite(name string) (remote *api.Site, ETag string, err error)
+	GetSites() (remotes []api.Site, err error)
+	JoinSite(remote api.SitePost) (op Operation, err error)
+	UpdateSiteName(name string) (op Operation, err error)
+	DeleteSite(name string) (op Operation, err error)
+
 	// Warning functions
 	GetWarningUUIDs() (uuids []string, err error)
 	GetWarnings() (warnings []api.Warning, err error)
@@ -675,8 +682,7 @@ type InstanceConsoleArgs struct {
 
 // The InstanceConsoleLogArgs struct is used to pass additional options during a
 // instance console log request.
-type InstanceConsoleLogArgs struct {
-}
+type InstanceConsoleLogArgs struct{}
 
 // The InstanceExecArgs struct is used to pass additional options during instance exec.
 type InstanceExecArgs struct {
diff --git a/client/lxd_sites.go b/client/lxd_sites.go
new file mode 100644
index 000000000000..53ec02e4dc20
--- /dev/null
+++ b/client/lxd_sites.go
@@ -0,0 +1,85 @@
+package lxd
+
+import (
+	"fmt"
+
+	"github.com/canonical/lxd/shared/api"
+)
+
+// GetServerSites returns all sites.
+func (r *ProtocolLXD) GetSites() ([]api.Site, error) {
+	err := r.CheckExtension("sites")
+	if err != nil {
+		return nil, err
+	}
+
+	sites := []api.Site{}
+	_, err = r.queryStruct("GET", "/sites/", nil, "", &sites)
+	if err != nil {
+		return nil, err
+	}
+
+	return sites, nil
+}
+
+// GetSite returns information about a site.
+func (r *ProtocolLXD) GetSite(name string) (*api.Site, string, error) {
+	err := r.CheckExtension("sites")
+	if err != nil {
+		return nil, "", err
+	}
+
+	site := &api.Site{}
+	etag, err := r.queryStruct("GET", fmt.Sprintf("/sites/%s", name), nil, "", &site)
+	if err != nil {
+		return nil, "", err
+	}
+
+	return site, etag, nil
+}
+
+// JoinSite requests add a new site.
+func (r *ProtocolLXD) JoinSite(site api.SitePost) (Operation, error) {
+	err := r.CheckExtension("sites")
+	if err != nil {
+		return nil, err
+	}
+
+	op, _, err := r.queryOperation("POST", "/site/join", site, "", true)
+	if err != nil {
+		return nil, err
+	}
+
+	return op, nil
+}
+
+// UpdateSiteName updates a site's name.
+func (r *ProtocolLXD) UpdateSiteName(name string) (Operation, error) {
+	// TODO: expand function to provide support for updating site addresses.
+	err := r.CheckExtension("sites")
+	if err != nil {
+		return nil, err
+	}
+
+	op, _, err := r.queryOperation("PUT", fmt.Sprintf("/sites/%s", name), nil, "", true)
+	if err != nil {
+		return nil, err
+	}
+
+	return op, nil
+}
+
+// DeleteSite deletes a site.
+func (r *ProtocolLXD) DeleteSite(name string) (Operation, error) {
+	err := r.CheckExtension("sites")
+	if err != nil {
+		return nil, err
+	}
+
+	op, _, err := r.queryOperation("DELETE", fmt.Sprintf("/sites/%s", name), nil, "", true)
+	if err != nil {
+		return nil, err
+	}
+
+	return op, nil
+}