diff --git a/jdaviz/configs/default/plugins/markers/markers.py b/jdaviz/configs/default/plugins/markers/markers.py
index ed06f00910..754eee5d8c 100644
--- a/jdaviz/configs/default/plugins/markers/markers.py
+++ b/jdaviz/configs/default/plugins/markers/markers.py
@@ -139,7 +139,6 @@ def _on_viewer_key_event(self, viewer, data):
                 raise ValueError(f'failed to add {row_info} to table: {repr(err)}')
 
             x, y = row_info['axes_x'], row_info['axes_y']
-            # TODO: will need to test/update when adding support for display units
             self._get_mark(viewer).append_xy(getattr(x, 'value', x), getattr(y, 'value', y))
 
     def clear_table(self):
diff --git a/jdaviz/configs/default/plugins/viewers.py b/jdaviz/configs/default/plugins/viewers.py
index 7023f19671..70f33aa657 100644
--- a/jdaviz/configs/default/plugins/viewers.py
+++ b/jdaviz/configs/default/plugins/viewers.py
@@ -216,6 +216,10 @@ def jdaviz_helper(self):
         """The Jdaviz configuration helper tied to the viewer."""
         return self.jdaviz_app._jdaviz_helper
 
+    @property
+    def hub(self):
+        return self.session.hub
+
     @property
     def reference_id(self):
         return self._reference_id
diff --git a/jdaviz/core/marks.py b/jdaviz/core/marks.py
index 7c2cc5a223..08ffba76b9 100644
--- a/jdaviz/core/marks.py
+++ b/jdaviz/core/marks.py
@@ -7,6 +7,7 @@
 from glue.core import HubListener
 from specutils import Spectrum1D
 
+from jdaviz.core.events import GlobalDisplayUnitChanged
 from jdaviz.core.events import (SliceToolStateMessage, LineIdentifyMessage,
                                 SpectralMarksChangedMessage,
                                 RedshiftMessage)
@@ -485,6 +486,20 @@ def _on_shadowing_changed(self, change):
 
 
 class PluginMark():
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.xunit = None
+        self.yunit = None
+        # whether to update existing marks when global display units are changed
+        self.auto_update_units = True
+        self.hub.subscribe(self, GlobalDisplayUnitChanged,
+                           handler=self._on_global_display_unit_changed)
+        self._update_units()
+
+    @property
+    def hub(self):
+        return self.viewer.hub
+
     def update_xy(self, x, y):
         self.x = np.asarray(x)
         self.y = np.asarray(y)
@@ -493,24 +508,79 @@ def append_xy(self, x, y):
         self.x = np.append(self.x, x)
         self.y = np.append(self.y, y)
 
+    def _update_units(self):
+        if not self.auto_update_units:
+            return
+        if self.xunit is None:
+            self.set_x_unit()
+        if self.yunit is None:
+            self.set_y_unit()
+
+    def set_x_unit(self, unit=None):
+        if unit is None:
+            if not hasattr(self.viewer.state, 'x_display_unit'):
+                return
+            unit = self.viewer.state.x_display_unit
+        unit = u.Unit(unit)
+        if self.xunit is not None:
+            x = (self.x * self.xunit).to_value(unit, u.spectral())
+            self.xunit = unit
+            self.x = x
+        self.xunit = unit
+
+    def set_y_unit(self, unit=None):
+        if unit is None:
+            if not hasattr(self.viewer.state, 'y_display_unit'):
+                return
+            unit = self.viewer.state.y_display_unit
+        unit = u.Unit(unit)
+        if self.yunit is not None:
+            self.y = (self.y * self.yunit).to_value(unit)
+        self.yunit = unit
+
+    def _on_global_display_unit_changed(self, msg):
+        if not self.auto_update_units:
+            return
+        if self.viewer.__class__.__name__ in ['SpecvizProfileView', 'CubevizProfileView']:
+            axis_map = {'spectral': 'x', 'flux': 'y'}
+        elif self.viewer.__class__.__name__ == 'MosvizProfile2DView':
+            axis_map = {'spectral': 'x'}
+        else:
+            return
+        axis = axis_map.get(msg.axis, None)
+        if axis is not None:
+            getattr(self, f'set_{axis}_unit')(msg.unit)
+
     def clear(self):
         self.update_xy([], [])
 
 
+class LinesAutoUnit(PluginMark, Lines, HubListener):
+    def __init__(self, viewer, *args, **kwargs):
+        self.viewer = viewer
+        super().__init__(*args, **kwargs)
+
+
 class PluginLine(Lines, PluginMark, HubListener):
     def __init__(self, viewer, x=[], y=[], **kwargs):
+        self.viewer = viewer
         # color is same blue as import button
         super().__init__(x=x, y=y, colors=["#007BA1"], scales=viewer.scales, **kwargs)
 
 
 class PluginScatter(Scatter, PluginMark, HubListener):
     def __init__(self, viewer, x=[], y=[], **kwargs):
+        self.viewer = viewer
         # color is same blue as import button
         super().__init__(x=x, y=y, colors=["#007BA1"], scales=viewer.scales, **kwargs)
 
 
 class LineAnalysisContinuum(PluginLine):
-    pass
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        # units do not need to be updated because the plugin itself reruns
+        # the computation and automatically changes the arrays themselves
+        self.auto_update_units = False
 
 
 class LineAnalysisContinuumCenter(LineAnalysisContinuum):
@@ -529,9 +599,9 @@ class LineAnalysisContinuumRight(LineAnalysisContinuumLeft):
     pass
 
 
-class LineUncertainties(Lines):
-    def __init__(self, **kwargs):
-        super().__init__(**kwargs)
+class LineUncertainties(LinesAutoUnit):
+    def __init__(self, viewer, *args, **kwargs):
+        super().__init__(viewer, *args, **kwargs)
 
 
 class ScatterMask(Scatter):