diff --git a/PyReconstruct/modules/datatypes/default_settings.py b/PyReconstruct/modules/datatypes/default_settings.py
index 3fee2ee7..c34f7486 100644
--- a/PyReconstruct/modules/datatypes/default_settings.py
+++ b/PyReconstruct/modules/datatypes/default_settings.py
@@ -88,6 +88,7 @@ def get_username() -> str:
     "homeview_act": "Home",
     "selectall_act": "Ctrl+A",
     "deselect_act": "Ctrl+D",
+    "invertselection_act": "Ctrl+Shift+I",
     "edittrace_act": "Ctrl+E",
     "mergetraces_act": "Ctrl+M",
     "mergeobjects_act": "Ctrl+Shift+M",
diff --git a/PyReconstruct/modules/datatypes/section.py b/PyReconstruct/modules/datatypes/section.py
index 9f9ee740..56b34127 100644
--- a/PyReconstruct/modules/datatypes/section.py
+++ b/PyReconstruct/modules/datatypes/section.py
@@ -667,7 +667,37 @@ def selectAllTraces(self):
         self.deselectAllTraces()
         for trace in self.tracesAsList():
             self.addSelectedTrace(trace)
-    
+
+    def invertTraceSelection(self, include_hidden=False):
+        """Invert the trace selection: deselect every selected trace and
+        select every unselected trace.
+
+        Only traces visible in the field can become selected: hidden and
+        group-hidden traces are skipped unless include_hidden is True (the
+        show-all-traces mode). Locked objects are never selected
+        (addSelectedTrace refuses them). Selected ztrace points and flags are
+        left untouched.
+
+        (Only meant for GUI use.)
+
+            Params:
+                include_hidden (bool): True if hidden traces may be selected
+        """
+        selected = set(self.selected_traces)
+        group_hidden = set(self.traces_group_hide)
+
+        to_select = []
+        for trace in self.tracesAsList():
+            if trace in selected:
+                continue
+            if not include_hidden and (trace.hidden or trace in group_hidden):
+                continue
+            to_select.append(trace)
+
+        self.selected_traces : list[Trace] = []
+        for trace in to_select:
+            self.addSelectedTrace(trace)
+
     def hideTraces(self, traces : list = None, hide=True, log_event=True):
         """Hide traces.
 
diff --git a/PyReconstruct/modules/gui/dialog/shortcuts.py b/PyReconstruct/modules/gui/dialog/shortcuts.py
index 8d735f17..72f6365d 100644
--- a/PyReconstruct/modules/gui/dialog/shortcuts.py
+++ b/PyReconstruct/modules/gui/dialog/shortcuts.py
@@ -160,6 +160,7 @@ def getStaticShortcuts(w : QWidget) -> list[QKeySequence]:
     "Field Interactions",
     ("selectall_act", "Select all traces on section"),
     ("deselect_act", "Deselect all traces on section"),
+    ("invertselection_act", "Invert selected traces on section"),
     ("edittrace_act", "Edit attributes of selected trace(s)"),
     ("mergetraces_act", "Merge selected traces"),
     ("mergeobjects_act", "Merge attributes of selected traces"),
diff --git a/PyReconstruct/modules/gui/main/context_menu_list.py b/PyReconstruct/modules/gui/main/context_menu_list.py
index 8fac77c9..054fc2ff 100644
--- a/PyReconstruct/modules/gui/main/context_menu_list.py
+++ b/PyReconstruct/modules/gui/main/context_menu_list.py
@@ -48,6 +48,7 @@ def get_field_menu_list(self):
         None,
         ("selectall_act", "Select all traces", self.series, self.field.selectAllTraces),
         ("deselect_act", "Deselect traces", self.series, self.field.deselectAllTraces),
+        ("invertselection_act", "Invert selection", self.series, self.field.invertTraceSelection),
         None,
         ("delete_act", "Delete", "Del", self.backspace),
     ]
@@ -94,6 +95,8 @@ def get_context_menu_list_obj(self):
                 None,
                 ("hideobj_act", "Hide", "", self.hideObj),
                 ("unhideobj_act", "Unhide", "", lambda : self.hideObj(False)),
+                ("hideunselectedobj_act", "Hide unselected objects", "", self.hideUnselectedObjects),
+                ("showallobj_act", "Show all objects", "", self.unhideAllObjects),
                 None,
                 ("removealltags_act", "Remove all tags", "", self.removeAllTags),
                 None,
diff --git a/PyReconstruct/modules/gui/main/field_widget_2_trace.py b/PyReconstruct/modules/gui/main/field_widget_2_trace.py
index e2edf754..3eff1218 100644
--- a/PyReconstruct/modules/gui/main/field_widget_2_trace.py
+++ b/PyReconstruct/modules/gui/main/field_widget_2_trace.py
@@ -417,6 +417,14 @@ def selectAllTraces(self):
         self.section.selectAllTraces()
         self.generateView(generate_image=False)
 
+    def invertTraceSelection(self):
+        """Invert which traces are selected on the section."""
+        # disable if trace layer is hidden
+        if self.hide_trace_layer:
+            return
+        self.section.invertTraceSelection(include_hidden=self.show_all_traces)
+        self.generateView(generate_image=False)
+
     ############################################################################
     ## Interactions only accessible through the field ##########################
     ############################################################################
diff --git a/PyReconstruct/modules/gui/main/field_widget_3_object.py b/PyReconstruct/modules/gui/main/field_widget_3_object.py
index f82721e2..8b672c97 100644
--- a/PyReconstruct/modules/gui/main/field_widget_3_object.py
+++ b/PyReconstruct/modules/gui/main/field_widget_3_object.py
@@ -364,6 +364,51 @@ def hideObj(self, obj_names : list, hide=True):
 
         return True
 
+    # update_objects=False so the decorator does NOT run its locked-check on the
+    # selection (the SELECTED objects are the ones being kept, not modified) and
+    # does not refresh the wrong rows -- both are handled against the complement
+    # below.
+    @object_function(update_objects=False, reload_field=True)
+    def hideUnselectedObjects(self, obj_names : list):
+        """Isolate the selected object(s): hide every OTHER object throughout the
+        whole series, so the isolation persists as sections change.
+
+        Objects in the complement are hidden regardless of their locked state --
+        locking guards edits and quantification, not visibility. An empty
+        selection is a no-op (the decorator returns before we get here), so this
+        can never blank the series.
+
+            Params:
+                obj_names (list): the objects to keep visible (object-list
+                    selection, or the objects owning the field's selected traces)
+            Returns:
+                (bool): True if any object was hidden
+        """
+        keep = set(obj_names)
+        others = [name for name in self.series.data["objects"] if name not in keep]
+        if not others:  # everything is already selected -> nothing to hide
+            return False
+
+        self.series.hideObjects(others, True, self.series_states)
+        self.table_manager.updateObjects(others)
+
+        return True
+
+    def unhideAllObjects(self):
+        """Show all objects: unhide every object throughout the whole series.
+
+        The clear restore for "Hide unselected objects"; undoable series-wide,
+        like the object hide itself.
+        """
+        all_names = list(self.series.data["objects"].keys())
+        if not all_names:
+            return
+        self.mainwindow.saveAllData()
+        self.series.hideObjects(all_names, False, self.series_states)
+        self.table_manager.updateObjects(all_names)
+        self.mainwindow.seriesModified(True)
+        self.reload()
+
     @object_function(update_objects=False, reload_field=False)
     def addTo3D(self, obj_names : list):
         """Generate a 3D view of an object"""
diff --git a/PyReconstruct/modules/gui/table/object.py b/PyReconstruct/modules/gui/table/object.py
index 3eee2460..63325c75 100644
--- a/PyReconstruct/modules/gui/table/object.py
+++ b/PyReconstruct/modules/gui/table/object.py
@@ -12,7 +12,7 @@
     QPalette,
     QColor
 )
-from PySide6.QtCore import Qt
+from PySide6.QtCore import Qt, QItemSelection, QItemSelectionModel
 
 from .data_table import DataTable
 from .history import HistoryTableWidget
@@ -36,6 +36,23 @@
     TextWidget,
 )
 
+
+def invert_object_rows(row_names : list, selected : set):
+    """Return the row indices to select when inverting an object selection.
+
+    Every row that is not currently selected becomes selected. Object rows are
+    freely selectable in the list (no lock restriction), so nothing is excluded
+    here -- this matches the object list's existing selection behavior.
+
+        Params:
+            row_names (list): object name at each row, in row order
+            selected (set): names of the currently selected objects
+        Returns:
+            (list): the row indices that should end up selected
+    """
+    return [r for r, name in enumerate(row_names) if name not in selected]
+
+
 class ObjectTableWidget(DataTable):
     
     def __init__(self, series : Series, mainwindow : QWidget, manager, hidden=False):
@@ -130,6 +147,17 @@ def getCall(col_name, opt_name):
                     ("export_act", "Export...", "", self.export),
                 ]
             },
+            {
+                "attr_name": "selectionmenu",
+                "text": "Selection",
+                "opts":
+                [
+                    ("invertobjselection_act", "Invert selection", "", self.invertSelection),
+                    None,
+                    ("hideunselectedobj_act1", "Hide unselected objects", "", self.mainwindow.field.hideUnselectedObjects),
+                    ("showallobj_act1", "Show all objects", "", self.mainwindow.field.unhideAllObjects),
+                ]
+            },
             {
                 "attr_name": "filtermenu",
                 "text": "Filter",
@@ -194,8 +222,13 @@ def getCall(col_name, opt_name):
         # fill in the menu bar object
         populateMenuBar(self, self.menubar, menubar_list)
 
-        # create the right-click menu
-        context_menu_list = self.mainwindow.field.getObjMenu()
+        # create the right-click menu -- prepend the object-list-only
+        # "Invert selection" (a table selection op, so it lives here rather
+        # than in the shared field object menu)
+        context_menu_list = [
+            ("invertobjselection_act1", "Invert selection", "", self.invertSelection),
+            None,
+        ] + self.mainwindow.field.getObjMenu()
         self.context_menu = QMenu(self)
         populateMenu(self, self.context_menu, context_menu_list)
 
@@ -575,6 +608,32 @@ def getSelected(self, single=False):
         else:
             return obj_names
 
+    def invertSelection(self):
+        """Invert which objects are selected in the list.
+
+        Every object shown in the list that is not currently selected becomes
+        selected, and vice versa. Operates on the rows currently displayed, so
+        with no active filter this inverts against every object in the series.
+        """
+        row_count = self.table.rowCount()
+        if not row_count:
+            return
+
+        row_names = [self.table.item(r, 0).text() for r in range(row_count)]
+        selected = set(self.getSelected())
+        to_select = invert_object_rows(row_names, selected)
+
+        model = self.table.model()
+        last_col = self.table.columnCount() - 1
+        new_selection = QItemSelection()
+        for r in to_select:
+            new_selection.select(model.index(r, 0), model.index(r, last_col))
+
+        self.table.selectionModel().select(
+            new_selection,
+            QItemSelectionModel.ClearAndSelect
+        )
+
     def itemChanged(self, item : QTableWidgetItem):
         """User checked a checkbox."""
         # check for curation