diff --git a/.changeset/wise-walls-cover.md b/.changeset/wise-walls-cover.md
new file mode 100644
index 00000000000..22599477f67
--- /dev/null
+++ b/.changeset/wise-walls-cover.md
@@ -0,0 +1,5 @@
+---
+'@shopify/polaris': patch
+---
+
+Refactored `Box` border radius properties to fix issues with cascading styles
diff --git a/polaris-react/src/components/Box/Box.scss b/polaris-react/src/components/Box/Box.scss
index cfc2181d7e6..79f3330edf1 100644
--- a/polaris-react/src/components/Box/Box.scss
+++ b/polaris-react/src/components/Box/Box.scss
@@ -26,10 +26,10 @@
   --pc-box-shadow: initial;
   --pc-box-background: initial;
   --pc-box-border-radius: initial;
-  --pc-box-border-radius-end-start: initial;
-  --pc-box-border-radius-end-end: initial;
-  --pc-box-border-radius-start-start: initial;
-  --pc-box-border-radius-start-end: initial;
+  --pc-box-border-radius-end-start: var(--pc-box-border-radius);
+  --pc-box-border-radius-end-end: var(--pc-box-border-radius);
+  --pc-box-border-radius-start-start: var(--pc-box-border-radius);
+  --pc-box-border-radius-start-end: var(--pc-box-border-radius);
   --pc-box-color: initial;
   --pc-box-min-height: initial;
   --pc-box-min-width: initial;
@@ -64,31 +64,17 @@
   background-color: var(--pc-box-background);
   // stylelint-disable-next-line -- generated by polaris-migrator DO NOT COPY
   box-shadow: var(--pc-box-shadow);
-  // stylelint-disable-next-line -- generated by polaris-migrator DO NOT COPY
-  border-radius: var(--pc-box-border-radius);
   // stylelint-disable -- generated by polaris-migrator DO NOT COPY
-  border-end-start-radius: var(
-    --pc-box-border-radius-end-start,
-    var(--pc-box-border-radius)
-  );
+  border-end-start-radius: var(--pc-box-border-radius-end-start);
   // stylelint-enable
   // stylelint-disable -- generated by polaris-migrator DO NOT COPY
-  border-end-end-radius: var(
-    --pc-box-border-radius-end-end,
-    var(--pc-box-border-radius)
-  );
+  border-end-end-radius: var(--pc-box-border-radius-end-end);
   // stylelint-enable
   // stylelint-disable -- generated by polaris-migrator DO NOT COPY
-  border-start-start-radius: var(
-    --pc-box-border-radius-start-start,
-    var(--pc-box-border-radius)
-  );
+  border-start-start-radius: var(--pc-box-border-radius-start-start);
   // stylelint-enable
   // stylelint-disable -- generated by polaris-migrator DO NOT COPY
-  border-start-end-radius: var(
-    --pc-box-border-radius-start-end,
-    var(--pc-box-border-radius)
-  );
+  border-start-end-radius: var(--pc-box-border-radius-start-end);
   // stylelint-enable
   // stylelint-disable-next-line -- component custom property that maps to Polaris tokens
   border-color: var(--pc-box-border-color);