diff --git a/openmc/mgxs/library.py b/openmc/mgxs/library.py
index 4c173f81a9..87c6665b2d 100644
--- a/openmc/mgxs/library.py
+++ b/openmc/mgxs/library.py
@@ -53,6 +53,8 @@ class Library(object):
         The types of cross sections in the library (e.g., ['total', 'scatter'])
     domain_type : {'material', 'cell', 'distribcell', 'universe'}
         Domain type for spatial homogenization
+    domains : Iterable of Material, Cell or Universe
+        The spatial domain(s) for which MGXS in the Library are computed
     correction : 'P0' or None
         Apply the P0 correction to scattering matrices if set to 'P0'
     energy_groups : EnergyGroups
@@ -80,6 +82,7 @@ class Library(object):
         self._by_nuclide = None
         self._mgxs_types = []
         self._domain_type = None
+        self._domains = 'all'
         self._correction = 'P0'
         self._energy_groups = None
         self._tally_trigger = None
@@ -105,6 +108,7 @@ class Library(object):
             clone._by_nuclide = self.by_nuclide
             clone._mgxs_types = self.mgxs_types
             clone._domain_type = self.domain_type
+            clone._domains = self.domains
             clone._correction = self.correction
             clone._energy_groups = copy.deepcopy(self.energy_groups, memo)
             clone._tally_trigger = copy.deepcopy(self.tally_trigger, memo)
@@ -153,22 +157,24 @@ class Library(object):
     def by_nuclide(self):
         return self._by_nuclide
 
-    @property
-    def domains(self):
-        if self.domain_type is None:
-            raise ValueError('Unable to get all domains without a domain type')
-
-        if self.domain_type == 'material':
-            return self.openmc_geometry.get_all_materials()
-        elif self.domain_type == 'cell' or self.domain_type == 'distribcell':
-            return self.openmc_geometry.get_all_material_cells()
-        elif self.domain_type == 'universe':
-            return self.openmc_geometry.get_all_universes()
-
     @property
     def domain_type(self):
         return self._domain_type
 
+    @property
+    def domains(self):
+        if self._domains == 'all':
+            if self.domain_type == 'material':
+                return self.openmc_geometry.get_all_materials()
+            elif self.domain_type in ['cell', 'distribcell']:
+                return self.openmc_geometry.get_all_material_cells()
+            elif self.domain_type == 'universe':
+                return self.openmc_geometry.get_all_universes()
+            else:
+                raise ValueError('Unable to get domains without a domain type')
+        else:
+            return self._domains
+
     @property
     def correction(self):
         return self._correction
@@ -223,6 +229,38 @@ class Library(object):
         cv.check_value('domain type', domain_type, tuple(openmc.mgxs.DOMAIN_TYPES))
         self._domain_type = domain_type
 
+    @domains.setter
+    def domains(self, domains):
+
+        # Use all materials, cells or universes in the geometry as domains
+        if domains == 'all':
+            self._domains = domains
+
+        # User specified a list of material, cell or universe domains
+        else:
+            if self.domain_type == 'material':
+                cv.check_iterable_type('domain', domains, openmc.Material)
+                all_domains = self.openmc_geometry.get_all_materials()
+            elif self.domain_type in ['cell', 'distribcell']:
+                cv.check_iterable_type('domain', domains, openmc.Cell)
+                all_domains = self.openmc_geometry.get_all_material_cells()
+            elif self.domain_type == 'universe':
+                cv.check_iterable_type('domain', domains, openmc.Universe)
+                all_domains = self.openmc_geometry.get_all_universes()
+            else:
+                msg = 'Unable to set domains with ' \
+                      'domain type "{}"'.format(self.domain_type)
+                raise ValueError(msg)
+
+            # Check that each domain can be found in the geometry
+            for domain in domains:
+                if domain not in all_domains:
+                    msg = 'Domain "{}" could not be found in the ' \
+                          'geometry.'.format(domain)
+                    raise ValueError(msg)
+
+            self._domains = domains
+
     @correction.setter
     def correction(self, correction):
         cv.check_value('correction', correction, ('P0', None))