diff --git a/src/app.css b/src/app.css
index 8e48a78e..fcf4b0cd 100644
--- a/src/app.css
+++ b/src/app.css
@@ -1438,6 +1438,7 @@ body:has(.media-modal-container + .status-deck) .media-post-link {
   display: inline-block;
   margin: 4px;
   align-self: center;
+  text-align: center;
 
   &.clickable {
     cursor: pointer;
diff --git a/src/components/account-info.css b/src/components/account-info.css
index 43b70526..0cd656ff 100644
--- a/src/components/account-info.css
+++ b/src/components/account-info.css
@@ -165,6 +165,76 @@
   animation: fade-in 0.3s both ease-in-out 0.2s;
 }
 
+.private-note-tag {
+  z-index: 1;
+  appearance: none;
+  display: inline-block;
+  color: var(--private-note-text-color);
+  background-color: var(--private-note-bg-color);
+  border: 1px solid var(--private-note-border-color);
+  padding: 4px;
+  line-height: normal;
+  font-size: smaller;
+  border-radius: 0;
+  align-self: center !important;
+  /* clip a dog ear on top right */
+  clip-path: polygon(0 0, calc(100% - 4px) 0, 100% 4px, 100% 100%, 0 100%);
+  /* 4x4px square on top right */
+  background-size: 4px 4px;
+  background-repeat: no-repeat;
+  background-position: top right;
+  background-image: linear-gradient(
+    to bottom,
+    var(--private-note-border-color),
+    var(--private-note-border-color)
+  );
+  transition: transform 0.15s ease-in-out;
+
+  span {
+    color: inherit;
+    opacity: 0.75;
+    text-overflow: ellipsis;
+    overflow: hidden;
+    display: -webkit-box;
+    display: box;
+    -webkit-box-orient: vertical;
+    box-orient: vertical;
+    -webkit-line-clamp: 2;
+    line-clamp: 2;
+    text-align: left;
+  }
+
+  &:hover:not(:active) {
+    filter: none !important;
+    transform: rotate(-0.5deg) scale(1.05);
+
+    span {
+      opacity: 1;
+    }
+  }
+}
+.account-container .private-note {
+  font-size: 90%;
+  color: var(--text-insignificant-color);
+  text-overflow: ellipsis;
+  overflow: hidden;
+  white-space: nowrap;
+  padding: 12px;
+  background-color: var(--bg-faded-color);
+  display: flex;
+  gap: 0.5em;
+  align-items: center;
+
+  b {
+    font-size: 90%;
+    text-transform: uppercase;
+  }
+  p {
+    margin: 0;
+    padding: 0;
+  }
+}
+
 .account-container .note {
   font-size: 95%;
   line-height: 1.4;
@@ -228,10 +298,11 @@
   align-items: center;
 }
 .account-container .actions button {
-  align-self: flex-end;
+  /* align-self: flex-end; */
 }
 .account-container .actions .buttons {
   display: flex;
+  align-items: center;
 }
 
 .account-container .account-metadata-box {
@@ -571,3 +642,30 @@
       drop-shadow(8px 0 8px var(--header-color-4, --bg-color));
   }
 }
+
+#private-note-container {
+  textarea {
+    margin-top: 8px;
+    width: 100%;
+    resize: vertical;
+    height: 33vh;
+    min-height: 25vh;
+    max-height: 50vh;
+    color: var(--private-note-text-color);
+    background-color: var(--private-note-bg-color);
+    border: 1px solid var(--private-note-border-color);
+    box-shadow: 0 2px 8px var(--drop-shadow-color);
+    border-radius: 0;
+    padding: 16px;
+  }
+
+  footer {
+    display: flex;
+    justify-content: space-between;
+    padding: 8px 0;
+
+    * {
+      vertical-align: middle;
+    }
+  }
+}
diff --git a/src/components/account-info.jsx b/src/components/account-info.jsx
index d5ac62c4..b97e9762 100644
--- a/src/components/account-info.jsx
+++ b/src/components/account-info.jsx
@@ -772,6 +772,7 @@ function RelatedActions({
     requested,
     domainBlocking,
     endorsed,
+    note: privateNote,
   } = relationship || {};
 
   const [currentInfo, setCurrentInfo] = useState(null);
@@ -853,6 +854,7 @@ function RelatedActions({
 
   const [showTranslatedBio, setShowTranslatedBio] = useState(false);
   const [showAddRemoveLists, setShowAddRemoveLists] = useState(false);
+  const [showPrivateNoteModal, setShowPrivateNoteModal] = useState(false);
 
   return (
     <>
@@ -863,9 +865,11 @@ function RelatedActions({
           ) : !!lastStatusAt ? (
             <small class="insignificant">
               Last post:{' '}
-              {niceDateTime(lastStatusAt, {
-                hideTime: true,
-              })}
+              <span class="ib">
+                {niceDateTime(lastStatusAt, {
+                  hideTime: true,
+                })}
+              </span>
             </small>
           ) : (
             <span />
@@ -874,6 +878,19 @@ function RelatedActions({
           {blocking && <span class="tag danger">Blocked</span>}
         </span>{' '}
         <span class="buttons">
+          {!!privateNote && (
+            <button
+              type="button"
+              class="private-note-tag"
+              title="Private note"
+              onClick={() => {
+                setShowPrivateNoteModal(true);
+              }}
+              dir="auto"
+            >
+              <span>{privateNote}</span>
+            </button>
+          )}
           <Menu
             instanceRef={menuInstanceRef}
             portal={{
@@ -927,6 +944,16 @@ function RelatedActions({
                   <Icon icon="translate" />
                   <span>Translate bio</span>
                 </MenuItem>
+                <MenuItem
+                  onClick={() => {
+                    setShowPrivateNoteModal(true);
+                  }}
+                >
+                  <Icon icon="pencil" />
+                  <span>
+                    {privateNote ? 'Edit private note' : 'Add private note'}
+                  </span>
+                </MenuItem>
                 {/* Add/remove from lists is only possible if following the account */}
                 {following && (
                   <MenuItem
@@ -1237,6 +1264,24 @@ function RelatedActions({
           />
         </Modal>
       )}
+      {!!showPrivateNoteModal && (
+        <Modal
+          class="light"
+          onClose={() => {
+            setShowPrivateNoteModal(false);
+          }}
+        >
+          <PrivateNoteSheet
+            account={info}
+            note={privateNote}
+            onRelationshipChange={(relationship) => {
+              setRelationship(relationship);
+              // onRelationshipChange({ relationship, currentID: accountID.current });
+            }}
+            onClose={() => setShowPrivateNoteModal(false)}
+          />
+        </Modal>
+      )}
     </>
   );
 }
@@ -1434,4 +1479,95 @@ function AddRemoveListsSheet({ accountID, onClose }) {
   );
 }
 
+function PrivateNoteSheet({
+  account,
+  note: initialNote,
+  onRelationshipChange = () => {},
+  onClose = () => {},
+}) {
+  const { masto } = api();
+  const [uiState, setUIState] = useState('default');
+  const textareaRef = useRef(null);
+
+  useEffect(() => {
+    let timer;
+    if (textareaRef.current && !initialNote) {
+      timer = setTimeout(() => {
+        textareaRef.current.focus?.();
+      }, 100);
+    }
+    return () => {
+      clearTimeout(timer);
+    };
+  }, []);
+
+  return (
+    <div class="sheet" id="private-note-container">
+      {!!onClose && (
+        <button type="button" class="sheet-close" onClick={onClose}>
+          <Icon icon="x" />
+        </button>
+      )}
+      <header>
+        <b>Private note for @{account?.acct}</b>
+      </header>
+      <main>
+        <form
+          onSubmit={(e) => {
+            e.preventDefault();
+            const formData = new FormData(e.target);
+            const note = formData.get('note');
+            if (note?.trim() !== initialNote?.trim()) {
+              setUIState('loading');
+              (async () => {
+                try {
+                  const newRelationship = await masto.v1.accounts
+                    .$select(account?.id)
+                    .note.create({
+                      comment: note,
+                    });
+                  console.log('updated relationship', newRelationship);
+                  setUIState('default');
+                  onRelationshipChange(newRelationship);
+                  onClose();
+                } catch (e) {
+                  console.error(e);
+                  setUIState('error');
+                  alert(e?.message || 'Unable to update private note.');
+                }
+              })();
+            }
+          }}
+        >
+          <textarea
+            ref={textareaRef}
+            name="note"
+            disabled={uiState === 'loading'}
+          >
+            {initialNote}
+          </textarea>
+          <footer>
+            <button
+              type="button"
+              class="light"
+              disabled={uiState === 'loading'}
+              onClick={() => {
+                onClose?.();
+              }}
+            >
+              Cancel
+            </button>
+            <span>
+              <Loader abrupt hidden={uiState !== 'loading'} />
+              <button disabled={uiState === 'loading'} type="submit">
+                Save &amp; close
+              </button>
+            </span>
+          </footer>
+        </form>
+      </main>
+    </div>
+  );
+}
+
 export default AccountInfo;
diff --git a/src/index.css b/src/index.css
index 98a1ce08..8508da46 100644
--- a/src/index.css
+++ b/src/index.css
@@ -62,6 +62,9 @@
   --close-button-bg-active-color: rgba(0, 0, 0, 0.2);
   --close-button-color: rgba(0, 0, 0, 0.5);
   --close-button-hover-color: rgba(0, 0, 0, 1);
+  --private-note-text-color: var(--text-color);
+  --private-note-bg-color: color-mix(in srgb, yellow 20%, var(--bg-color));
+  --private-note-border-color: rgba(0, 0, 0, 0.2);
 
   /* Video colors won't change based on color scheme */
   --media-fg-color: #f0f2f5;
@@ -111,6 +114,7 @@
     --close-button-bg-active-color: rgba(255, 255, 255, 0.15);
     --close-button-color: rgba(255, 255, 255, 0.5);
     --close-button-hover-color: rgba(255, 255, 255, 1);
+    --private-note-border-color: rgba(255, 255, 255, 0.2);
   }
 }