diff --git a/source/blender/blenkernel/BKE_text.h b/source/blender/blenkernel/BKE_text.h
index a69fee19380..12f8795ae2a 100644
--- a/source/blender/blenkernel/BKE_text.h
+++ b/source/blender/blenkernel/BKE_text.h
@@ -94,6 +94,9 @@ void txt_sel_clear(struct Text *text);
 void txt_sel_line(struct Text *text);
 void txt_sel_set(struct Text *text, int startl, int startc, int endl, int endc);
 char *txt_sel_to_buf(const struct Text *text, size_t *r_buf_strlen);
+/**
+ * \param in_buffer: UTF8 encoded text, invalid UTF8 byte-sequences are handled gracefully.
+ */
 void txt_insert_buf(struct Text *text, const char *in_buffer, int in_buffer_len)
     ATTR_NONNULL(1, 2);
 void txt_split_curline(struct Text *text);
diff --git a/source/blender/editors/curve/editfont.c b/source/blender/editors/curve/editfont.c
index 5d2ee150ea0..460ef112521 100644
--- a/source/blender/editors/curve/editfont.c
+++ b/source/blender/editors/curve/editfont.c
@@ -1051,7 +1051,8 @@ static int paste_text_exec(bContext *C, wmOperator *op)
     int len;
   } clipboard_system = {NULL}, clipboard_vfont = {NULL};
 
-  clipboard_system.buf = WM_clipboard_text_get(selection, &clipboard_system.len);
+  /* No need for UTF8 validation as the conversion handles invalid sequences gracefully. */
+  clipboard_system.buf = WM_clipboard_text_get(selection, false, &clipboard_system.len);
 
   if (clipboard_system.buf == NULL) {
     return OPERATOR_CANCELLED;
diff --git a/source/blender/editors/interface/interface_handlers.cc b/source/blender/editors/interface/interface_handlers.cc
index 683509d2d6b..749f74d253c 100644
--- a/source/blender/editors/interface/interface_handlers.cc
+++ b/source/blender/editors/interface/interface_handlers.cc
@@ -2435,19 +2435,21 @@ static void ui_apply_but(
 /** \name Button Copy & Paste
  * \{ */
 
-static void ui_but_get_pasted_text_from_clipboard(char **buf_paste, int *buf_len)
+static void ui_but_get_pasted_text_from_clipboard(const bool ensure_utf8,
+                                                  char **r_buf_paste,
+                                                  int *r_buf_len)
 {
   /* get only first line even if the clipboard contains multiple lines */
   int length;
-  char *text = WM_clipboard_text_get_firstline(false, &length);
+  char *text = WM_clipboard_text_get_firstline(false, ensure_utf8, &length);
 
   if (text) {
-    *buf_paste = text;
-    *buf_len = length;
+    *r_buf_paste = text;
+    *r_buf_len = length;
   }
   else {
-    *buf_paste = static_cast<char *>(MEM_callocN(sizeof(char), __func__));
-    *buf_len = 0;
+    *r_buf_paste = static_cast<char *>(MEM_callocN(sizeof(char), __func__));
+    *r_buf_len = 0;
   }
 }
 
@@ -2831,7 +2833,7 @@ static void ui_but_paste(bContext *C, uiBut *but, uiHandleButtonData *data, cons
 
   int buf_paste_len = 0;
   char *buf_paste;
-  ui_but_get_pasted_text_from_clipboard(&buf_paste, &buf_paste_len);
+  ui_but_get_pasted_text_from_clipboard(UI_but_is_utf8(but), &buf_paste, &buf_paste_len);
 
   const bool has_required_data = !(but->poin == nullptr && but->rnapoin.data == nullptr);
 
@@ -3310,13 +3312,9 @@ static bool ui_textedit_copypaste(uiBut *but, uiHandleButtonData *data, const in
   if (mode == UI_TEXTEDIT_PASTE) {
     /* extract the first line from the clipboard */
     int buf_len;
-    char *pbuf = WM_clipboard_text_get_firstline(false, &buf_len);
+    char *pbuf = WM_clipboard_text_get_firstline(false, UI_but_is_utf8(but), &buf_len);
 
     if (pbuf) {
-      if (UI_but_is_utf8(but)) {
-        buf_len -= BLI_str_utf8_invalid_strip(pbuf, size_t(buf_len));
-      }
-
       ui_textedit_insert_buf(but, data, pbuf, buf_len);
 
       changed = true;
@@ -3508,9 +3506,12 @@ static void ui_textedit_end(bContext *C, uiBut *but, uiHandleButtonData *data)
   if (but) {
     if (UI_but_is_utf8(but)) {
       const int strip = BLI_str_utf8_invalid_strip(but->editstr, strlen(but->editstr));
-      /* not a file?, strip non utf-8 chars */
+      /* Strip non-UTF8 characters unless buttons support this.
+       * This should never happen as all text input should be valid UTF8,
+       * there is a small chance existing data contains invalid sequences.
+       * This could check could be made into an assertion if `but->editstr`
+       * is valid UTF8 when #ui_textedit_begin assigns the string. */
       if (strip) {
-        /* won't happen often so isn't that annoying to keep it here for a while */
         printf("%s: invalid utf8 - stripped chars %d\n", __func__, strip);
       }
     }
diff --git a/source/blender/editors/space_console/console_ops.c b/source/blender/editors/space_console/console_ops.c
index 507156d8341..0152054d4c7 100644
--- a/source/blender/editors/space_console/console_ops.c
+++ b/source/blender/editors/space_console/console_ops.c
@@ -1064,7 +1064,7 @@ static int console_paste_exec(bContext *C, wmOperator *op)
   ConsoleLine *ci = console_history_verify(C);
   int buf_len;
 
-  char *buf_str = WM_clipboard_text_get(selection, &buf_len);
+  char *buf_str = WM_clipboard_text_get(selection, true, &buf_len);
   char *buf_step, *buf_next;
 
   if (buf_str == NULL) {
diff --git a/source/blender/editors/space_text/text_ops.c b/source/blender/editors/space_text/text_ops.c
index 58dffa36b2d..ecd9607396c 100644
--- a/source/blender/editors/space_text/text_ops.c
+++ b/source/blender/editors/space_text/text_ops.c
@@ -923,7 +923,8 @@ static int text_paste_exec(bContext *C, wmOperator *op)
   char *buf;
   int buf_len;
 
-  buf = WM_clipboard_text_get(selection, &buf_len);
+  /* No need for UTF8 validation as the conversion handles invalid sequences gracefully. */
+  buf = WM_clipboard_text_get(selection, false, &buf_len);
 
   if (!buf) {
     return OPERATOR_CANCELLED;
diff --git a/source/blender/editors/util/numinput.c b/source/blender/editors/util/numinput.c
index bdd3149884c..16e2caffb58 100644
--- a/source/blender/editors/util/numinput.c
+++ b/source/blender/editors/util/numinput.c
@@ -506,7 +506,7 @@ bool handleNumInput(bContext *C, NumInput *n, const wmEvent *event)
       if (event->modifier & KM_CTRL) {
         /* extract the first line from the clipboard */
         int pbuf_len;
-        char *pbuf = WM_clipboard_text_get_firstline(false, &pbuf_len);
+        char *pbuf = WM_clipboard_text_get_firstline(false, true, &pbuf_len);
 
         if (pbuf) {
           const bool success = editstr_insert_at_cursor(n, pbuf, pbuf_len);
diff --git a/source/blender/python/intern/bpy_rna_types_capi.c b/source/blender/python/intern/bpy_rna_types_capi.c
index 105a1008a89..ae37be2f761 100644
--- a/source/blender/python/intern/bpy_rna_types_capi.c
+++ b/source/blender/python/intern/bpy_rna_types_capi.c
@@ -111,7 +111,8 @@ PyDoc_STRVAR(pyrna_WindowManager_clipboard_doc, "Clipboard text storage.\n\n:typ
 static PyObject *pyrna_WindowManager_clipboard_get(PyObject *UNUSED(self), void *UNUSED(flag))
 {
   int text_len = 0;
-  char *text = WM_clipboard_text_get(false, &text_len);
+  /* No need for UTF8 validation as #PyC_UnicodeFromBytesAndSize handles invalid byte sequences. */
+  char *text = WM_clipboard_text_get(false, false, &text_len);
   PyObject *result = PyC_UnicodeFromBytesAndSize(text ? text : "", text_len);
   if (text != NULL) {
     MEM_freeN(text);
diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index 5117c87db7f..6f6c5513514 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -1624,14 +1624,15 @@ void WM_job_main_thread_lock_release(struct wmJob *job);
 
 /**
  * Return text from the clipboard.
- *
- * \note Caller needs to check for valid utf8 if this is a requirement.
+ * \param selection: Use the "primary" clipboard, see: #WM_CAPABILITY_PRIMARY_CLIPBOARD.
+ * \param ensure_utf8: Ensure the resulting string does not contain invalid UTF8 encoding.
  */
-char *WM_clipboard_text_get(bool selection, int *r_len);
+char *WM_clipboard_text_get(bool selection, bool ensure_utf8, int *r_len);
 /**
  * Convenience function for pasting to areas of Blender which don't support newlines.
  */
-char *WM_clipboard_text_get_firstline(bool selection, int *r_len);
+char *WM_clipboard_text_get_firstline(bool selection, bool ensure_utf8, int *r_len);
+
 void WM_clipboard_text_set(const char *buf, bool selection);
 
 /**
diff --git a/source/blender/windowmanager/intern/wm_window.c b/source/blender/windowmanager/intern/wm_window.c
index d7f0f3944d6..6eb362a97e2 100644
--- a/source/blender/windowmanager/intern/wm_window.c
+++ b/source/blender/windowmanager/intern/wm_window.c
@@ -1983,7 +1983,10 @@ void WM_event_remove_timer_notifier(wmWindowManager *wm, wmWindow *win, wmTimer
 /** \name Clipboard
  * \{ */
 
-static char *wm_clipboard_text_get_ex(bool selection, int *r_len, bool firstline)
+static char *wm_clipboard_text_get_ex(bool selection,
+                                      int *r_len,
+                                      const bool ensure_utf8,
+                                      const bool firstline)
 {
   if (G.background) {
     *r_len = 0;
@@ -1996,8 +1999,18 @@ static char *wm_clipboard_text_get_ex(bool selection, int *r_len, bool firstline
     return NULL;
   }
 
+  int buf_len = strlen(buf);
+
+  if (ensure_utf8) {
+    /* TODO(@ideasman42): It would be good if unexpected byte sequences could be interpreted
+     * instead of stripped - so mixed in characters (typically Latin1) aren't ignored.
+     * Check on how Python bytes this, see: #PyC_UnicodeFromBytesAndSize,
+     * there are clever ways to handle this although they increase the size of the buffer. */
+    buf_len -= BLI_str_utf8_invalid_strip(buf, buf_len);
+  }
+
   /* always convert from \r\n to \n */
-  char *newbuf = MEM_mallocN(strlen(buf) + 1, __func__);
+  char *newbuf = MEM_mallocN(buf_len + 1, __func__);
   char *p2 = newbuf;
 
   if (firstline) {
@@ -2028,14 +2041,14 @@ static char *wm_clipboard_text_get_ex(bool selection, int *r_len, bool firstline
   return newbuf;
 }
 
-char *WM_clipboard_text_get(bool selection, int *r_len)
+char *WM_clipboard_text_get(bool selection, bool ensure_utf8, int *r_len)
 {
-  return wm_clipboard_text_get_ex(selection, r_len, false);
+  return wm_clipboard_text_get_ex(selection, r_len, ensure_utf8, false);
 }
 
-char *WM_clipboard_text_get_firstline(bool selection, int *r_len)
+char *WM_clipboard_text_get_firstline(bool selection, bool ensure_utf8, int *r_len)
 {
-  return wm_clipboard_text_get_ex(selection, r_len, true);
+  return wm_clipboard_text_get_ex(selection, r_len, ensure_utf8, true);
 }
 
 void WM_clipboard_text_set(const char *buf, bool selection)