diff --git a/onnxscript/function_libs/torch_lib/ops/core.py b/onnxscript/function_libs/torch_lib/ops/core.py
index d9b576a3f6..dd142a6b5c 100644
--- a/onnxscript/function_libs/torch_lib/ops/core.py
+++ b/onnxscript/function_libs/torch_lib/ops/core.py
@@ -14,7 +14,7 @@
 import math
 from typing import Any, Optional, Sequence, Tuple, Union
 
-from onnxscript import BOOL, DOUBLE, FLOAT, INT8, INT16, INT32, INT64
+from onnxscript import BOOL, DOUBLE, FLOAT, INT8, INT16, INT32, INT64, graph
 from onnxscript.function_libs.torch_lib.registration import torch_op
 from onnxscript.function_libs.torch_lib.tensor_typing import (
     IntType,
@@ -666,22 +666,86 @@ def aten_atanh(self: TFloat) -> TFloat:
     return op.Atanh(self)
 
 
-def aten_atleast_1d(self: TensorType) -> TensorType:
+@torch_op("aten::atleast_1d")
+def aten_atleast_1d(self: Sequence[TTensor]) -> TTensor:
     """atleast_1d(Tensor self) -> Tensor"""
 
-    raise NotImplementedError()
+    @graph()
+    def reshape_to_1d(tensor):
+        shape = op.Shape(tensor)
+        rank = op.Size(shape)
+        if rank == 0:
+            tensor = op.Reshape(tensor, op.Constant(value_ints=[1]))
+        return tensor
+
+    return op.SequenceMap(self, body=reshape_to_1d)
+
+
+@torch_op("aten::atleast_1d")
+def aten_atleast_1d_single_tensor(self: TTensor) -> TTensor:
+    """atleast_1d(Tensor self) -> Tensor"""
+
+    shape = op.Shape(self)
+    rank = op.Size(shape)
+    if rank == 0:
+        self = op.Reshape(self, op.Constant(value_ints=[1]))
+    return self
 
 
-def aten_atleast_2d(self: TensorType) -> TensorType:
+@torch_op("aten::atleast_2d")
+def aten_atleast_2d(self: Sequence[TTensor]) -> TTensor:
     """atleast_2d(Tensor self) -> Tensor"""
 
-    raise NotImplementedError()
+    @graph()
+    def reshape_to_2d(tensor):
+        shape = op.Shape(tensor)
+        rank = op.Size(shape)
+        if rank <= 1:
+            tensor = op.Reshape(tensor, op.Constant(value_ints=[1, -1]))
+        return tensor
+
+    return op.SequenceMap(self, body=reshape_to_2d)
+
+
+@torch_op("aten::atleast_2d")
+def aten_atleast_2d_single_tensor(self: TTensor) -> TTensor:
+    """atleast_2d(Tensor self) -> Tensor"""
+
+    shape = op.Shape(self)
+    rank = op.Size(shape)
+    if rank <= 1:
+        self = op.Reshape(self, op.Constant(value_ints=[1, -1]))
+    return self
 
 
-def aten_atleast_3d(self: TensorType) -> TensorType:
+@torch_op("aten::atleast_3d")
+def aten_atleast_3d(self: Sequence[TTensor]) -> TTensor:
     """atleast_3d(Tensor self) -> Tensor"""
 
-    raise NotImplementedError()
+    @graph()
+    def reshape_to_3d(tensor):
+        shape = op.Shape(tensor)
+        rank = op.Size(shape)
+        if rank <= 1:
+            tensor = op.Reshape(tensor, op.Constant(value_ints=[1, -1, 1]))
+        elif rank == 2:
+            tensor = op.Unsqueeze(tensor, op.Constant(value_ints=[-1]))
+        return tensor
+
+    return op.SequenceMap(self, body=reshape_to_3d)
+
+
+@torch_op("aten::atleast_3d")
+def aten_atleast_3d_single_tensor(self: TTensor) -> TTensor:
+    """atleast_3d(Tensor self) -> Tensor"""
+
+    shape = op.Shape(self)
+    rank = op.Size(shape)
+    if rank <= 1:
+        self = op.Reshape(self, op.Constant(value_ints=[1, -1, 1]))
+    elif rank == 2:
+        self = op.Unsqueeze(self, op.Constant(value_ints=[-1]))
+    return self
 
 
 def aten_avg_pool1d(
diff --git a/onnxscript/tests/function_libs/torch_lib/ops_test_data.py b/onnxscript/tests/function_libs/torch_lib/ops_test_data.py
index fc9c1eda26..a4ab21a5a9 100644
--- a/onnxscript/tests/function_libs/torch_lib/ops_test_data.py
+++ b/onnxscript/tests/function_libs/torch_lib/ops_test_data.py
@@ -344,6 +344,12 @@ def _where_input_wrangler(
     "atan": core_ops.aten_atan,
     "atan2": core_ops.aten_atan2,
     "atanh": core_ops.aten_atanh,
+    "atleast_1d": core_ops.aten_atleast_1d,
+    "atleast_1d_single_tensor": core_ops.aten_atleast_1d_single_tensor,
+    "atleast_2d": core_ops.aten_atleast_2d,
+    "atleast_2d_single_tensor": core_ops.aten_atleast_2d_single_tensor,
+    "atleast_3d": core_ops.aten_atleast_3d,
+    "atleast_3d_single_tensor": core_ops.aten_atleast_3d_single_tensor,
     "baddbmm": core_ops.aten_baddbmm,
     "bmm": core_ops.aten_bmm,
     "broadcast_to": core_ops.aten_broadcast_to,
@@ -808,6 +814,21 @@ def _where_input_wrangler(
         matcher=lambda sample: len(sample.args) != 2,
         reason="arange_start_step overload takes three arguments (input, start, step)",
     ),
+    skip(
+        "atleast_1d_single_tensor",
+        matcher=lambda sample: isinstance(sample.input, (list, tuple)),
+        reason="atleast_1d_single_tensor overload takes single tensor as input",
+    ),
+    skip(
+        "atleast_2d_single_tensor",
+        matcher=lambda sample: isinstance(sample.input, (list, tuple)),
+        reason="atleast_2d_single_tensor overload takes single tensor as input",
+    ),
+    skip(
+        "atleast_3d_single_tensor",
+        matcher=lambda sample: isinstance(sample.input, (list, tuple)),
+        reason="atleast_3d_single_tensor overload takes single tensor as input",
+    ),
     skip(
         "cat",
         matcher=lambda sample: sample.input[0].equal(torch.tensor([])),
@@ -1166,6 +1187,11 @@ def _where_input_wrangler(
     ),
 )
 
+ops_test_common.duplicate_opinfo(OPS_DB, "atleast_1d", ("atleast_1d_single_tensor",))
+ops_test_common.duplicate_opinfo(OPS_DB, "atleast_2d", ("atleast_2d_single_tensor",))
+ops_test_common.duplicate_opinfo(OPS_DB, "atleast_3d", ("atleast_3d_single_tensor",))
+
+
 ops_test_common.duplicate_opinfo(OPS_DB, "full_like", ("full_like_dtype",))
 
 ops_test_common.duplicate_opinfo(OPS_DB, "index_put", ("index_put_bool",))
@@ -1480,6 +1506,30 @@ def _where_input_wrangler(
         torch.float32,
         torch.float16,
     ),
+    "atleast_1d": (
+        torch.float32,
+        torch.float16,
+    ),
+    "atleast_1d_single_tensor": (
+        torch.float32,
+        torch.float16,
+    ),
+    "atleast_2d": (
+        torch.float32,
+        torch.float16,
+    ),
+    "atleast_2d_single_tensor": (
+        torch.float32,
+        torch.float16,
+    ),
+    "atleast_3d": (
+        torch.float32,
+        torch.float16,
+    ),
+    "atleast_3d_single_tensor": (
+        torch.float32,
+        torch.float16,
+    ),
     "baddbmm": (
         torch.float32,
         torch.float16,