diff --git a/core/src/css/themes/high-contrast-dark.scss b/core/src/css/themes/high-contrast-dark.scss
index a6e452cf61e..37b6e7166d5 100644
--- a/core/src/css/themes/high-contrast-dark.scss
+++ b/core/src/css/themes/high-contrast-dark.scss
@@ -97,6 +97,8 @@ $colors:  (
       --ion-color-#{$color-name}-shade: #{map.get($value, shade)};
       --ion-color-#{$color-name}-tint: #{map.get($value, tint)};
     }
+
+    --ion-placeholder-opacity: 0.8;
   }
 
   // Toast
diff --git a/core/src/css/themes/high-contrast-light.scss b/core/src/css/themes/high-contrast-light.scss
index e72770ad2f2..4a69322d100 100644
--- a/core/src/css/themes/high-contrast-light.scss
+++ b/core/src/css/themes/high-contrast-light.scss
@@ -88,6 +88,8 @@ $colors:  (
       --ion-color-#{$color-name}-shade: #{map.get($value, shade)};
       --ion-color-#{$color-name}-tint: #{map.get($value, tint)};
     }
+
+    --ion-placeholder-opacity: 0.8;
   }
 
   // Toast
diff --git a/core/src/themes/ionic.globals.scss b/core/src/themes/ionic.globals.scss
index d421a43b6ff..f4c52d1472b 100644
--- a/core/src/themes/ionic.globals.scss
+++ b/core/src/themes/ionic.globals.scss
@@ -35,7 +35,7 @@ $screen-breakpoints: (
 // Input placeholder opacity
 // Ensures that the placeholder has the
 // correct color contrast against the background.
-$placeholder-opacity: 0.6 !default;
+$placeholder-opacity: var(--ion-placeholder-opacity, 0.6) !default;
 
 $form-control-label-margin: 16px !default;