diff --git a/xarray/core/groupby.py b/xarray/core/groupby.py
index 9045ceed872..eb7eb7eb363 100644
--- a/xarray/core/groupby.py
+++ b/xarray/core/groupby.py
@@ -296,16 +296,16 @@ class ResolvedGrouper(Generic[T_DataWithCoords]):
     obj: T_DataWithCoords
 
     # returned by factorize:
-    codes: DataArray = field(init=False)
-    full_index: pd.Index = field(init=False)
-    group_indices: T_GroupIndices = field(init=False)
-    unique_coord: Variable | _DummyGroup = field(init=False)
+    codes: DataArray = field(init=False, repr=False)
+    full_index: pd.Index = field(init=False, repr=False)
+    group_indices: T_GroupIndices = field(init=False, repr=False)
+    unique_coord: Variable | _DummyGroup = field(init=False, repr=False)
 
     # _ensure_1d:
-    group1d: T_Group = field(init=False)
-    stacked_obj: T_DataWithCoords = field(init=False)
-    stacked_dim: Hashable | None = field(init=False)
-    inserted_dims: list[Hashable] = field(init=False)
+    group1d: T_Group = field(init=False, repr=False)
+    stacked_obj: T_DataWithCoords = field(init=False, repr=False)
+    stacked_dim: Hashable | None = field(init=False, repr=False)
+    inserted_dims: list[Hashable] = field(init=False, repr=False)
 
     def __post_init__(self) -> None:
         # This copy allows the BinGrouper.factorize() method
diff --git a/xarray/core/groupers.py b/xarray/core/groupers.py
index a71da16c718..e905280280e 100644
--- a/xarray/core/groupers.py
+++ b/xarray/core/groupers.py
@@ -117,7 +117,7 @@ class Resampler(Grouper):
 class UniqueGrouper(Grouper):
     """Grouper object for grouping by a categorical variable."""
 
-    _group_as_index: pd.Index | None = None
+    _group_as_index: pd.Index | None = field(default=None, repr=False)
 
     @property
     def is_unique_and_monotonic(self) -> bool:
@@ -336,8 +336,8 @@ class TimeResampler(Resampler):
     loffset: datetime.timedelta | str | None = field(default=None)
     base: int | None = field(default=None)
 
-    index_grouper: CFTimeGrouper | pd.Grouper = field(init=False)
-    group_as_index: pd.Index = field(init=False)
+    index_grouper: CFTimeGrouper | pd.Grouper = field(init=False, repr=False)
+    group_as_index: pd.Index = field(init=False, repr=False)
 
     def __post_init__(self):
         if self.loffset is not None: