diff --git a/source/blender/windowmanager/intern/wm_files.cc b/source/blender/windowmanager/intern/wm_files.cc
index 0b96a199105..f51ca4725a6 100644
--- a/source/blender/windowmanager/intern/wm_files.cc
+++ b/source/blender/windowmanager/intern/wm_files.cc
@@ -90,6 +90,8 @@
 #include "RNA_access.hh"
 #include "RNA_define.hh"
 
+#include "GPU_immediate.h"
+
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
 #include "IMB_thumbs.h"
@@ -830,6 +832,113 @@ static void wm_file_read_post(bContext *C,
   WM_cursor_wait(false);
 }
 
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name File Loading Dialog
+ * \{ */
+
+/**
+ * Window callback to draw a darkened area behind the loading dialog.
+ */
+static void loading_dialog_background_cb(const wmWindow *win, void *)
+{
+  GPU_blend(GPU_BLEND_ALPHA);
+  GPUVertFormat *format = immVertexFormat();
+  int pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
+  immBindBuiltinProgram(GPU_SHADER_3D_UNIFORM_COLOR);
+  immUniformColor4f(0.0f, 0.0f, 0.0f, 0.5f);
+  immBegin(GPU_PRIM_TRI_STRIP, 4);
+  immVertex2f(pos, WM_window_pixels_x(win), 0.0f);
+  immVertex2f(pos, 0.0f, 0.0f);
+  immVertex2f(pos, WM_window_pixels_x(win), WM_window_pixels_y(win));
+  immVertex2f(pos, 0.0f, WM_window_pixels_y(win));
+  immEnd();
+  immUnbindProgram();
+}
+
+/**
+ * Dialog displayed during blend file loading, showing thumbnail and file name.
+ */
+static uiBlock *wm_block_create_loading(bContext *C, ARegion *region, void *arg)
+{
+  const char *filepath = static_cast<const char *>(arg);
+  short preview_width = int((114.0f * UI_SCALE_FAC));
+
+  /* First look for preview in the local thumbnail cache folder. */
+  ImBuf *ibuf = IMB_thumb_read(filepath, THB_LARGE);
+
+  if (!ibuf) {
+    /* Not in cache, so extract from the blend file itself. */
+    BlendThumbnail *data = BLO_thumbnail_from_file(filepath);
+    ibuf = data ? BKE_main_thumbnail_to_imbuf(nullptr, data) : nullptr;
+    if (data) {
+      MEM_freeN(data);
+    }
+  }
+
+  const uchar *color = nullptr;
+
+  if (!ibuf) {
+    /* No thumbnails found, so just use Blender logo. */
+    ibuf = UI_icon_alert_imbuf_get(ALERT_ICON_BLENDER);
+    color = UI_GetTheme()->tui.wcol_menu_back.text_sel;
+    IMB_premultiply_alpha(ibuf);
+  }
+
+  /* Size to fit within preview_width x preview_width. */
+  float scale = float(preview_width) / float(MAX2(ibuf->x, ibuf->y));
+  IMB_scaleImBuf(ibuf, scale * ibuf->x, scale * ibuf->y);
+  preview_width = ibuf->x;
+
+  const uiStyle *style = UI_style_get_dpi();
+  const int text_points_max = MAX2(style->widget.points, style->widgetlabel.points);
+  const int dialog_width = preview_width + (text_points_max * 23 * UI_SCALE_FAC);
+  const float padding = 5.0f * UI_SCALE_FAC;
+  const float split_factor = (float(preview_width) + padding) /
+                             float(dialog_width - style->columnspace);
+
+  uiBlock *block = UI_block_begin(C, region, "file_open_loading_popup", UI_EMBOSS);
+  UI_block_theme_style_set(block, UI_BLOCK_THEME_STYLE_POPUP);
+
+  uiLayout *block_layout = UI_block_layout(
+      block, UI_LAYOUT_VERTICAL, UI_LAYOUT_PANEL, 0, 0, dialog_width, 0, 0, style);
+
+  /* Split layout to put preview on left side. */
+  uiLayout *split_block = uiLayoutSplit(block_layout, split_factor, false);
+
+  /* Preview on the left. */
+  uiLayout *layout = uiLayoutRow(split_block, false);
+  /* Using 'align_left' with 'row' avoids stretching the icon along the width of column. */
+  uiLayoutSetAlignment(layout, UI_LAYOUT_ALIGN_LEFT);
+
+  uiDefButImage(block, ibuf, 0, U.widget_unit, ibuf->x, ibuf->y, color);
+
+  /* The rest of the content on the right. */
+  layout = uiLayoutColumn(split_block, false);
+
+  uiItemS(layout);
+
+  uiItemL_ex(layout, N_("Opening file..."), ICON_NONE, false, false);
+
+  char filename[FILE_MAX];
+  BLI_path_split_file_part(filepath, filename, sizeof(filename));
+  uiItemL_ex(layout, filename, ICON_NONE, true, false);
+
+  size_t filesize = BLI_file_size(filepath);
+  if (filesize > 0) {
+    char size_dec[BLI_STR_FORMAT_INT32_DECIMAL_UNIT_SIZE];
+    BLI_str_format_decimal_unit(size_dec, filesize);
+    uiItemL_ex(layout, size_dec, ICON_NONE, false, false);
+  }
+
+  uiItemS(layout);
+
+  UI_block_bounds_set_centered(block, 5 * UI_SCALE_FAC);
+
+  return block;
+}
+
 static void wm_read_callback_pre_wrapper(bContext *C, const char *filepath)
 {
   /* NOTE: either #BKE_CB_EVT_LOAD_POST or #BKE_CB_EVT_LOAD_POST_FAIL must run.
@@ -1022,9 +1131,18 @@ bool WM_file_read(bContext *C, const char *filepath, ReportList *reports)
       CTX_wm_window_set(C, win);
     }
     if (win != nullptr) {
-      /* Redraw to remove any open menus. */
+      /* Draw a darkened background across the window. */
+      void *cb = WM_draw_cb_activate(win, loading_dialog_background_cb, nullptr);
+
+      /* Set up the dialog. */
+      UI_popup_block_invoke(C, wm_block_create_loading, (void *)filepath, nullptr);
+
+      /* Redraw to remove any open menus and show loading block. */
       WM_redraw_windows(C);
 
+      /* No more need for the window-darkening callback. */
+      WM_draw_cb_exit(win, cb);
+
       if (win_was_null) {
         CTX_wm_window_set(C, nullptr);
       }