diff --git a/src/bokeh/plotting/_legends.py b/src/bokeh/plotting/_legends.py
index 36d3ab31178..e273d92892f 100644
--- a/src/bokeh/plotting/_legends.py
+++ b/src/bokeh/plotting/_legends.py
@@ -10,7 +10,10 @@
 #-----------------------------------------------------------------------------
 from __future__ import annotations
 
+from bokeh.util.strings import nice_join
+
 import logging # isort:skip
+
 log = logging.getLogger(__name__)
 
 #-----------------------------------------------------------------------------
@@ -52,9 +55,14 @@
 #-----------------------------------------------------------------------------
 
 def pop_legend_kwarg(kwargs: dict[str, Any]) -> tuple[Any, str]:
-    result = {attr: kwargs.pop(attr) for attr in LEGEND_ARGS if attr in kwargs}
-    if len(result) > 1:
-        from ..util.strings import nice_join
+    num_legend_args = 0
+    result = {}
+    for attr in LEGEND_ARGS:
+        if attr in kwargs:
+            result[attr] = kwargs.pop(attr)
+            num_legend_args += 1
+
+    if num_legend_args > 1:
 
         raise ValueError(f"Only one of {nice_join(LEGEND_ARGS)} may be provided, got: {nice_join(result.keys())}")
     legend_name = kwargs.pop("legend_name", None)
diff --git a/src/bokeh/util/strings.py b/src/bokeh/util/strings.py
index 15eb0a62271..c2594dde31e 100644
--- a/src/bokeh/util/strings.py
+++ b/src/bokeh/util/strings.py
@@ -61,7 +61,7 @@ def indent(text: str, n: int = 2, ch: str = " ") -> str:
 
 
 def nice_join(seq: Iterable[Any], *, sep: str = ", ", conjunction: str | None = "or") -> str:
-    ''' Join together sequences of strings into English-friendly phrases using
+    """ Join together sequences of strings into English-friendly phrases using
     the conjunction ``or`` when appropriate.
 
     Args:
@@ -77,13 +77,20 @@ def nice_join(seq: Iterable[Any], *, sep: str = ", ", conjunction: str | None =
         >>> nice_join(["a", "b", "c"])
         'a, b or c'
 
-    '''
-    seq = [str(x) for x in seq]
+    """
+    # Use map(str, ...) for better performance on string conversion
+    # Avoid building the list unless more than one element or conjunction is not None
+    if hasattr(seq, '__len__'):
+        n = len(seq)
+        str_seq = list(map(str, seq))
+    else:
+        str_seq = list(map(str, seq))
+        n = len(str_seq)
 
-    if len(seq) <= 1 or conjunction is None:
-        return sep.join(seq)
+    if n <= 1 or conjunction is None:
+        return sep.join(str_seq)
     else:
-        return f"{sep.join(seq[:-1])} {conjunction} {seq[-1]}"
+        return f"{sep.join(str_seq[:-1])} {conjunction} {str_seq[-1]}"
 
 
 def snakify(name: str, sep: str = "_") -> str: