diff --git a/janus_core/helpers/janus_types.py b/janus_core/helpers/janus_types.py
index 27c6c556..0f8c878b 100644
--- a/janus_core/helpers/janus_types.py
+++ b/janus_core/helpers/janus_types.py
@@ -115,7 +115,7 @@ class CorrelationKwargs(TypedDict, total=True):
 
 # Janus specific
 Architectures = Literal[
-    "mace", "mace_mp", "mace_off", "m3gnet", "chgnet", "alignn", "sevennet"
+    "mace", "mace_mp", "mace_off", "m3gnet", "chgnet", "alignn", "sevennet", "orb"
 ]
 Devices = Literal["cpu", "cuda", "mps", "xpu"]
 Ensembles = Literal["nph", "npt", "nve", "nvt", "nvt-nh"]
diff --git a/janus_core/helpers/mlip_calculators.py b/janus_core/helpers/mlip_calculators.py
index 537dc027..a1310c2c 100644
--- a/janus_core/helpers/mlip_calculators.py
+++ b/janus_core/helpers/mlip_calculators.py
@@ -225,6 +225,36 @@ def choose_calculator(
         kwargs.setdefault("sevennet_config", None)
         calculator = SevenNetCalculator(model=model_path, device=device, **kwargs)
 
+    elif arch == "orb":
+        from orb_models import __version__
+        from orb_models.forcefield.calculator import ORBCalculator
+        from orb_models.forcefield.graph_regressor import GraphRegressor
+        import orb_models.forcefield.pretrained as orb_ff
+
+        if isinstance(model_path, str):
+            match model_path:
+                case "orb-v1":
+                    model = orb_ff.orb_v1()
+                case "orb-mptraj-only-v1":
+                    model = orb_ff.orb_v1_mptraj_only()
+                case "orb-d3-v1":
+                    model = orb_ff.orb_d3_v1()
+                case "orb-d3-xs-v1":
+                    model = orb_ff.orb_d3_xs_v1()
+                case "orb-d3-sm-v1":
+                    model = orb_ff.orb_d3_sm_v1()
+                case _:
+                    raise ValueError(
+                        "Please specify `model_path`, as there is no "
+                        f"default model for {arch}"
+                    )
+        elif isinstance(model_path, GraphRegressor):
+            model = model_path
+        else:
+            model = orb_ff.orb_v1_mptraj_only()
+
+        calculator = ORBCalculator(model=model, device=device, **kwargs)
+
     else:
         raise ValueError(
             f"Unrecognized {arch=}. Suported architectures "
diff --git a/pyproject.toml b/pyproject.toml
index a481a7d9..2097bb14 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,6 +48,10 @@ m3gnet = [
     "matgl == 1.1.3",
     "dgl == 2.1.0",
 ]
+orb = [
+    "orb-models == 0.4.1",
+    "pynanoflann",
+]
 sevennet = [
     "sevenn == 0.10.0",
 ]
@@ -55,6 +59,7 @@ all = [
     "janus-core[alignn]",
     "janus-core[chgnet]",
     "janus-core[m3gnet]",
+    "janus-core[orb]",
     "janus-core[sevennet]",
 ]
 
@@ -164,3 +169,6 @@ default-groups = [
     "docs",
     "pre-commit",
 ]
+
+[tool.uv.sources]
+pynanoflann = { git = "https://github.com/dwastberg/pynanoflann", rev = "af434039ae14bedcbb838a7808924d6689274168" }