diff --git a/core/api.txt b/core/api.txt
index 33582d0fe55..063511d9884 100644
--- a/core/api.txt
+++ b/core/api.txt
@@ -566,7 +566,15 @@ ion-datetime,part,calendar-day
 ion-datetime,part,calendar-day active
 ion-datetime,part,calendar-day disabled
 ion-datetime,part,calendar-day today
+ion-datetime,part,calendar-days-of-week
+ion-datetime,part,calendar-header
+ion-datetime,part,datetime-header
+ion-datetime,part,datetime-selected-date
+ion-datetime,part,datetime-title
 ion-datetime,part,month-year-button
+ion-datetime,part,navigation-button
+ion-datetime,part,next-button
+ion-datetime,part,previous-button
 ion-datetime,part,time-button
 ion-datetime,part,time-button active
 ion-datetime,part,wheel
diff --git a/core/src/components/datetime/datetime.tsx b/core/src/components/datetime/datetime.tsx
index 95f97d37cf0..8c767eee5a9 100644
--- a/core/src/components/datetime/datetime.tsx
+++ b/core/src/components/datetime/datetime.tsx
@@ -88,14 +88,23 @@ import { checkForPresentationFormatMismatch, warnIfTimeZoneProvided } from './ut
  * layout with `presentation="date-time"` or `"time-date"`.
  * @part time-button active - The time picker button when the picker is open.
  *
+ * @part calendar-header - The calendar header manages the date navigation controls (month/year picker and previous/next buttons) and the days of the week when using a grid style layout.
  * @part month-year-button - The button that opens the month/year picker when
  * using a grid style layout.
+ * @part navigation-button - The buttons used to navigate to the next or previous month when using a grid style layout.
+ * @part previous-button - The button used to navigate to the previous month when using a grid style layout.
+ * @part next-button - The button used to navigate to the next month when using a grid style layout.
+ * @part calendar-days-of-week - The container for the day-of-the-week header (both weekdays and weekends) when using a grid style layout.
  *
  * @part calendar-day - The individual buttons that display a day inside of the datetime
  * calendar.
  * @part calendar-day active - The currently selected calendar day.
  * @part calendar-day today - The calendar day that contains the current day.
  * @part calendar-day disabled - The calendar day that is disabled.
+ *
+ * @part datetime-header - The datetime header contains the content for the `title` slot and the selected date.
+ * @part datetime-title - The element that contains the `title` slot content.
+ * @part datetime-selected-date - The element that contains the selected date.
  */
 @Component({
   tag: 'ion-datetime',
@@ -2166,7 +2175,7 @@ export class Datetime implements ComponentInterface {
     const hostDir = this.el.getAttribute('dir') || undefined;
 
     return (
-      <div class="calendar-header">
+      <div class="calendar-header" part="calendar-header">
         <div class="calendar-action-buttons">
           <div class="calendar-month-year">
             <button
@@ -2195,7 +2204,12 @@ export class Datetime implements ComponentInterface {
 
           <div class="calendar-next-prev">
             <ion-buttons>
-              <ion-button aria-label="Previous month" disabled={prevMonthDisabled} onClick={() => this.prevMonth()}>
+              <ion-button
+                aria-label="Previous month"
+                disabled={prevMonthDisabled}
+                onClick={() => this.prevMonth()}
+                part="navigation-button previous-button"
+              >
                 <ion-icon
                   dir={hostDir}
                   aria-hidden="true"
@@ -2205,7 +2219,12 @@ export class Datetime implements ComponentInterface {
                   flipRtl
                 ></ion-icon>
               </ion-button>
-              <ion-button aria-label="Next month" disabled={nextMonthDisabled} onClick={() => this.nextMonth()}>
+              <ion-button
+                aria-label="Next month"
+                disabled={nextMonthDisabled}
+                onClick={() => this.nextMonth()}
+                part="navigation-button next-button"
+              >
                 <ion-icon
                   dir={hostDir}
                   aria-hidden="true"
@@ -2218,7 +2237,7 @@ export class Datetime implements ComponentInterface {
             </ion-buttons>
           </div>
         </div>
-        <div class="calendar-days-of-week" aria-hidden="true">
+        <div class="calendar-days-of-week" aria-hidden="true" part="calendar-days-of-week">
           {getDaysOfWeek(this.locale, mode, this.firstDayOfWeek % 7).map((d) => {
             return <div class="day-of-week">{d}</div>;
           })}
@@ -2571,11 +2590,15 @@ export class Datetime implements ComponentInterface {
     }
 
     return (
-      <div class="datetime-header">
-        <div class="datetime-title">
+      <div class="datetime-header" part="datetime-header">
+        <div class="datetime-title" part="datetime-title">
           <slot name="title">Select Date</slot>
         </div>
-        {showExpandedHeader && <div class="datetime-selected-date">{this.getHeaderSelectedDateText()}</div>}
+        {showExpandedHeader && (
+          <div class="datetime-selected-date" part="datetime-selected-date">
+            {this.getHeaderSelectedDateText()}
+          </div>
+        )}
       </div>
     );
   }
diff --git a/core/src/components/datetime/test/custom/datetime.e2e.ts b/core/src/components/datetime/test/custom/datetime.e2e.ts
index 7ef408c0ef2..eb02f492327 100644
--- a/core/src/components/datetime/test/custom/datetime.e2e.ts
+++ b/core/src/components/datetime/test/custom/datetime.e2e.ts
@@ -175,6 +175,190 @@ configs({ directions: ['ltr'] }).forEach(({ title, screenshot, config }) => {
 
       expect(backgroundColor).toBe('rgb(0, 0, 255)');
     });
+
+    test('should be able to customize datetime header parts', async ({ page }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/30083',
+      });
+
+      await page.setContent(
+        `
+          <style>
+            ion-datetime::part(datetime-header) {
+              background-color: orange;
+            }
+
+            ion-datetime::part(datetime-title) {
+              background-color: pink;
+            }
+
+            ion-datetime::part(datetime-selected-date) {
+              background-color: violet;
+            }
+          </style>
+          <ion-datetime value="2020-03-14T14:23:00.000Z">
+            <span slot="title">Select Date</span>
+          </ion-datetime>
+        `,
+        config
+      );
+
+      const datetime = page.locator('ion-datetime');
+      const header = datetime.locator('.datetime-header');
+      const title = datetime.locator('.datetime-title');
+      const selectedDate = datetime.locator('.datetime-selected-date');
+
+      const headerBackgroundColor = await header.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      const titleBackgroundColor = await title.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      const selectedDateBackgroundColor = await selectedDate.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      expect(headerBackgroundColor).toBe('rgb(255, 165, 0)');
+      expect(titleBackgroundColor).toBe('rgb(255, 192, 203)');
+      expect(selectedDateBackgroundColor).toBe('rgb(238, 130, 238)');
+    });
+
+    test('should be able to customize calendar header part', async ({ page }) => {
+      await page.setContent(
+        `
+          <style>
+            ion-datetime::part(calendar-header) {
+              background-color: orange;
+            }
+          </style>
+          <ion-datetime value="2020-03-14T14:23:00.000Z"></ion-datetime>
+        `,
+        config
+      );
+
+      const datetime = page.locator('ion-datetime');
+      const header = datetime.locator('.calendar-header');
+
+      const backgroundColor = await header.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      expect(backgroundColor).toBe('rgb(255, 165, 0)');
+    });
+
+    test('should be able to customize month/year picker part', async ({ page }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/26596',
+      });
+
+      await page.setContent(
+        `
+          <style>
+            ion-datetime::part(month-year-button) {
+              background-color: lightblue;
+            }
+          </style>
+          <ion-datetime value="2020-03-14T14:23:00.000Z"></ion-datetime>
+        `,
+        config
+      );
+
+      const datetime = page.locator('ion-datetime');
+      const monthYearButton = datetime.locator('.calendar-month-year-toggle');
+
+      const backgroundColor = await monthYearButton.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      expect(backgroundColor).toBe('rgb(173, 216, 230)');
+    });
+
+    test('should be able to customize navigation button parts', async ({ page }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/30830',
+      });
+
+      await page.setContent(
+        `
+          <style>
+            ion-datetime::part(navigation-button) {
+              background-color: firebrick;
+            }
+
+            ion-datetime::part(previous-button) {
+              color: blue;
+            }
+
+            ion-datetime::part(next-button) {
+              color: green;
+            }
+          </style>
+          <ion-datetime value="2020-03-14T14:23:00.000Z"></ion-datetime>
+        `,
+        config
+      );
+
+      const datetime = page.locator('ion-datetime');
+      const prevButton = datetime.locator('.calendar-next-prev ion-button').first();
+      const nextButton = datetime.locator('.calendar-next-prev ion-button').last();
+
+      const prevBackgroundColor = await prevButton.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      const prevColor = await prevButton.evaluate((el) => {
+        return window.getComputedStyle(el).color;
+      });
+
+      const nextBackgroundColor = await nextButton.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      const nextColor = await nextButton.evaluate((el) => {
+        return window.getComputedStyle(el).color;
+      });
+
+      // Verify the navigation-button part applies the styles
+      expect(prevBackgroundColor).toBe('rgb(178, 34, 34)');
+      expect(nextBackgroundColor).toBe('rgb(178, 34, 34)');
+      // Verify the previous-button part applies the styles
+      expect(prevColor).toBe('rgb(0, 0, 255)');
+      // Verify the next-button part applies the styles
+      expect(nextColor).toBe('rgb(0, 128, 0)');
+    });
+
+    test('should be able to customize days of the week part', async ({ page }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/30830',
+      });
+
+      await page.setContent(
+        `
+          <style>
+            ion-datetime::part(calendar-days-of-week) {
+              background-color: green;
+            }
+          </style>
+          <ion-datetime value="2020-03-14T14:23:00.000Z"></ion-datetime>
+        `,
+        config
+      );
+
+      const datetime = page.locator('ion-datetime');
+      const daysOfWeek = datetime.locator('.calendar-days-of-week');
+
+      const backgroundColor = await daysOfWeek.evaluate((el) => {
+        return window.getComputedStyle(el).backgroundColor;
+      });
+
+      expect(backgroundColor).toBe('rgb(0, 128, 0)');
+    });
   });
 });
 
diff --git a/core/src/components/datetime/test/custom/index.html b/core/src/components/datetime/test/custom/index.html
index f0df8734521..0266e149616 100644
--- a/core/src/components/datetime/test/custom/index.html
+++ b/core/src/components/datetime/test/custom/index.html
@@ -134,6 +134,46 @@
         background-color: rgb(154 209 98 / 0.2);
         color: #9ad162;
       }
+
+      /*
+      * Custom Datetime Header Parts
+      * -------------------------------------------
+      */
+
+      #custom-grid::part(calendar-header),
+      #custom-title::part(datetime-header) {
+        background-color: orange;
+      }
+
+      #custom-grid::part(month-year-button) {
+        background-color: lightblue;
+        color: rgb(128, 30, 171);
+      }
+
+      #custom-grid::part(navigation-button) {
+        background-color: firebrick;
+      }
+
+      #custom-grid::part(previous-button) {
+        color: white;
+      }
+
+      #custom-grid::part(next-button) {
+        color: black;
+      }
+
+      #custom-grid::part(calendar-days-of-week) {
+        background-color: #9ad162;
+        color: white;
+      }
+
+      #custom-title::part(datetime-title) {
+        background-color: pink;
+      }
+
+      #custom-title::part(datetime-selected-date) {
+        background-color: violet;
+      }
     </style>
   </head>
 
@@ -163,6 +203,11 @@ <h2>Wheel Style</h2>
             <h2>Grid Style</h2>
             <ion-datetime id="custom-calendar-days" value="2023-06-15" presentation="date"></ion-datetime>
           </div>
+          <div class="grid-item">
+            <ion-datetime id="custom-title" presentation="date">
+              <span slot="title">Select Date</span>
+            </ion-datetime>
+          </div>
         </div>
       </ion-content>
     </ion-app>