Index: src/lang/english.txt
===================================================================
--- src/lang/english.txt	(revision 18696)
+++ src/lang/english.txt	(working copy)
@@ -3611,6 +3611,12 @@
 STR_ERROR_CAN_T_CHANGE_SIGN_NAME                                :{WHITE}Can't change sign name...
 STR_ERROR_CAN_T_DELETE_SIGN                                     :{WHITE}Can't delete sign...
 
+# GUI Sign list filter
+STR_FILTER                                                      :{BLACK}Filter
+STR_FILTER_OSKTITLE                                             :{BLACK}Enter a filter string
+STR_FILTER_MATCH_CASE                                           :{BLACK}Match case
+STR_FILTER_CLEAR                                                :{BLACK}Clear filter
+
 ##id 0x2000
 # Town building names
 STR_TOWN_BUILDING_NAME_TALL_OFFICE_BLOCK_1                      :Tall office block
Index: src/signs_gui.cpp
===================================================================
--- src/signs_gui.cpp	(revision 18696)
+++ src/signs_gui.cpp	(working copy)
@@ -28,12 +28,26 @@
 #include "table/strings.h"
 #include "table/sprites.h"
 
+struct FilterInfo {
+	const char *string;
+	bool case_sensitive;
+};
+
 struct SignList {
-	typedef GUIList<const Sign *> GUISignList;
+	typedef GUIList<const Sign *, FilterInfo> GUISignList;
 
 	static const Sign *last_sign;
 	GUISignList signs;
 
+	char filter_string[MAX_LENGTH_SIGN_NAME_BYTES];
+	bool match_case;
+
+	SignList()
+	{
+		memset(filter_string, '\0', sizeof(this->filter_string));
+		this->match_case = false;
+	}
+
 	void BuildSignsList()
 	{
 		if (!this->signs.NeedRebuild()) return;
@@ -45,6 +59,7 @@
 		const Sign *si;
 		FOR_ALL_SIGNS(si) *this->signs.Append() = si;
 
+		this->FilterSignList();
 		this->signs.Compact();
 		this->signs.RebuildDone();
 	}
@@ -74,6 +89,23 @@
 		/* Reset the name sorter sort cache */
 		this->last_sign = NULL;
 	}
+
+	/** Filter sign list by sign name (case sensitive setting in FilterInfo) */
+	static bool CDECL SignNameFilter(const Sign * const *a, FilterInfo filter_info)
+	{
+		/* Get sign string */
+		char buf1[64];
+		SetDParam(0, (*a)->index);
+		GetString(buf1, STR_SIGN_NAME, lastof(buf1));
+
+		return (filter_info.case_sensitive ? strstr(buf1, filter_info.string) : strcasestr(buf1, filter_info.string)) != NULL;
+	}
+
+	void FilterSignList()
+	{
+		FilterInfo filter_info = {this->filter_string, this->match_case};
+		this->signs.Filter(&SignNameFilter, filter_info);
+	}
 };
 
 const Sign *SignList::last_sign = NULL;
@@ -83,15 +115,31 @@
 	SLW_CAPTION,
 	SLW_LIST,
 	SLW_SCROLLBAR,
+	SLW_FILTER_TEXT,
+	SLW_FILTER_MATCH_CASE_BTN,
+	SLW_FILTER_CLEAR_BTN,
 };
 
-struct SignListWindow : Window, SignList {
+struct SignListWindow : QueryStringBaseWindow, SignList {
+private:
+	int selected_sign;
+
+public:
 	int text_offset; // Offset of the sign text relative to the left edge of the SLW_LIST widget.
 
-	SignListWindow(const WindowDesc *desc, WindowNumber window_number) : Window()
+	SignListWindow(const WindowDesc *desc, WindowNumber window_number) : QueryStringBaseWindow(MAX_LENGTH_SIGN_NAME_BYTES)
 	{
 		this->InitNested(desc, window_number);
 
+		/* Initialize the text edit widget */
+		this->afilter = CS_ALPHANUMERAL;
+		InitializeTextBuffer(&this->text, this->edit_str_buf, MAX_LENGTH_SIGN_NAME_BYTES, 255); // Allow MAX_LENGTH_SIGN_NAME_BYTES characters (including \0)
+		ClearFilterTextWidget();
+
+		/* Initialize the filtering variables */
+		this->SetFilterString("");
+		this->selected_sign = -1;
+
 		/* Create initial list. */
 		this->signs.ForceRebuild();
 		this->signs.ForceResort();
@@ -100,19 +148,93 @@
 		this->vscroll.SetCount(this->signs.Length());
 	}
 
+	void ClearFilterTextWidget()
+	{
+		this->edit_str_buf[0] = '\0';
+		UpdateTextBufferSize(&this->text);
+
+		this->SetWidgetDirty(SLW_FILTER_TEXT);
+	}
+
+	void SetFilterString(const char* new_filter_string)
+	{
+		/* clear this->filter_string */
+		memset(this->filter_string, '\0', sizeof(this->filter_string));
+
+		/* check if there is a new filter string */
+		if (new_filter_string != 0 && strlen(new_filter_string) != 0) {
+			/* Copy new filter string */
+			strncpy(this->filter_string, new_filter_string, strlen(new_filter_string));
+			this->filter_string[strlen(new_filter_string)] = '\0';
+
+			this->signs.SetFilterState(true);
+
+			this->EnableWidget(SLW_FILTER_CLEAR_BTN);
+		} else {
+			this->signs.SetFilterState(false);
+			this->DisableWidget(SLW_FILTER_CLEAR_BTN);
+			this->RaiseWidget(SLW_FILTER_CLEAR_BTN); // If a button is made disabled when it is lowered, it will not be raised by itself.
+			this->SetWidgetDirty(SLW_FILTER_CLEAR_BTN);
+		}
+
+		if ((this->selected_sign > -1) && ((uint)this->selected_sign >= this->signs.Length())) { // Can happen when a new filter is used.
+			this->selected_sign = this->signs.Length () - 1;
+		}
+
+		this->UpdateList();
+	}
+
+	void UpdateList()
+	{
+		/* Rebuild list of signs that are displayed and repaint the whole */
+		this->InvalidateData(0);
+		this->SetDirty();
+	}
+
+	void SelectNextSign()
+	{
+		this->selected_sign++;
+		if ((uint)this->selected_sign >= this->signs.Length()) {
+			this->selected_sign = this->signs.Length () - 1;
+		}
+
+		/* Scroll down a half page if moving below last line */
+		if (this->selected_sign >= this->vscroll.GetCapacity() + this->vscroll.GetPosition()) {
+			int pos = Clamp(this->vscroll.GetPosition() + this->vscroll.GetCapacity()/2 + 1,  0, this->vscroll.GetCount() - this->vscroll.GetCapacity());
+			this->vscroll.SetPosition(pos);
+		}
+
+		this->SetDirty();
+	}
+
+	void SelectPreviousSign()
+	{
+		this->selected_sign--;
+		if (this->selected_sign < 0) this->selected_sign = 0;
+
+		/* Scroll up a half page if moving above first line */
+		if (this->selected_sign < this->vscroll.GetPosition()) {
+			int pos = Clamp(this->vscroll.GetPosition() - this->vscroll.GetCapacity()/2 - 1,  0, this->vscroll.GetCount() - this->vscroll.GetCapacity());
+			this->vscroll.SetPosition(pos);
+		}
+
+		this->SetDirty();
+ 	}
+
 	virtual void OnPaint()
 	{
 		this->DrawWidgets();
+		if (!this->IsShaded()) this->DrawEditBox(SLW_FILTER_TEXT);
 	}
 
 	virtual void DrawWidget(const Rect &r, int widget) const
 	{
 		switch (widget) {
 			case SLW_LIST: {
-				uint y = r.top + WD_FRAMERECT_TOP; // Offset from top of widget.
+				uint y = r.top + 2; // Offset from top of widget.
 				/* No signs? */
 				if (this->vscroll.GetCount() == 0) {
-					DrawString(r.left + WD_FRAMETEXT_LEFT, r.right, y, STR_STATION_LIST_NONE);
+					DrawString(r.left + 2, r.right, y, STR_STATION_LIST_NONE);
 					return;
 				}
 
@@ -129,7 +251,11 @@
 					if (si->owner != OWNER_NONE) DrawCompanyIcon(si->owner, icon_left, y + sprite_offset_y);
 
 					SetDParam(0, si->index);
-					DrawString(text_left, text_right, y, STR_SIGN_NAME, TC_YELLOW);
+					if (this->selected_sign == i) {
+						DrawString(text_left, text_right, y, STR_SIGN_NAME, TC_BLUE);
+					} else {
+						DrawString(text_left, text_right, y, STR_SIGN_NAME, TC_YELLOW);
+					}
 					y += this->resize.step_height;
 				}
 				break;
@@ -144,18 +270,113 @@
 
 	virtual void OnClick(Point pt, int widget)
 	{
-		if (widget == SLW_LIST) {
-			uint id_v = (pt.y - this->GetWidget<NWidgetBase>(SLW_LIST)->pos_y - WD_FRAMERECT_TOP) / this->resize.step_height;
+		switch (widget) {
+			case SLW_LIST: { // <- needed or the compiler will complain
+				uint id_v = (pt.y - this->GetWidget<NWidgetBase>(SLW_LIST)->pos_y - WD_FRAMERECT_TOP) / this->resize.step_height;
 
-			if (id_v >= this->vscroll.GetCapacity()) return;
-			id_v += this->vscroll.GetPosition();
-			if (id_v >= this->vscroll.GetCount()) return;
+				if (id_v >= this->vscroll.GetCapacity()) return;
+				id_v += this->vscroll.GetPosition();
+				if (id_v >= this->vscroll.GetCount()) return;
 
-			const Sign *si = this->signs[id_v];
-			ScrollMainWindowToTile(TileVirtXY(si->x, si->y));
+				const Sign *si = this->signs[id_v];
+				ScrollMainWindowToTile(TileVirtXY(si->x, si->y));
+				break;
+			}
+			case SLW_FILTER_CLEAR_BTN:
+				this->ClearFilterTextWidget();
+				this->SetFilterString(0);
+				this->selected_sign = -1;
+				break;
+
+			case SLW_FILTER_MATCH_CASE_BTN:
+				this->match_case = !this->match_case;
+				if (this->match_case) {
+					this->LowerWidget(SLW_FILTER_MATCH_CASE_BTN);
+				} else {
+					this->RaiseWidget(SLW_FILTER_MATCH_CASE_BTN);
+				}
+				this->UpdateList();
+				break;
 		}
 	}
 
+	virtual void OnTimeout()
+	{
+		if (!this->IsWidgetDisabled(SLW_FILTER_CLEAR_BTN)) {
+			this->RaiseWidget(SLW_FILTER_CLEAR_BTN);
+			this->SetWidgetDirty(SLW_FILTER_CLEAR_BTN);
+		}
+	}
+
+	virtual EventState OnKeyPress(uint16 key, uint16 keycode)
+	{
+		EventState state = ES_NOT_HANDLED;
+		switch (this->HandleEditBoxKey(SLW_FILTER_TEXT, key, keycode, state)) {
+			case HEBR_EDITING:
+				this->SetFilterString(this->text.buf);
+				break;
+
+			case HEBR_CONFIRM: { // Enter pressed -> goto selected sign in list (or first if no selected sign)
+				uint n_signs = this->signs.Length();
+				if (n_signs >= 1) {
+					uint sign_id = this->selected_sign == -1 || (uint)this->selected_sign >= n_signs ? 0 : this->selected_sign;
+					if (n_signs > sign_id) {
+						const Sign* si = this->signs[sign_id];
+						ScrollMainWindowToTile(TileVirtXY(si->x, si->y));
+					}
+				}
+				return state;
+			}
+
+			case HEBR_CANCEL: // ESC pressed, clear filter
+				this->ClearFilterTextWidget(); // Empty the text in the EditBox widget
+				this->SetFilterString(0);      // Use empty text as filter text (= view all signs)
+				this->UnfocusFocusedWidget();  // Unfocus the text box
+				this->selected_sign = -1;      // Deselect sign in sign list
+				return state;
+
+			case HEBR_NOT_FOCUSED: // The filter text box is not globaly focused
+				if (keycode == 'F') { // Hotkey to enable filter box
+					this->SetFocusedWidget(SLW_FILTER_TEXT);
+					SetFocusedWindow(this); // The user has asked to give focus to the text box, so make sure this window is focused.
+
+					state = ES_HANDLED;
+				}
+				break;
+
+			default:
+				NOT_REACHED();
+		}
+
+		if (state == ES_HANDLED) OnOSKInput(SLW_FILTER_TEXT);
+
+		/* Selection of signs using arrow up/down keys */
+		if (this->IsWidgetGloballyFocused(SLW_FILTER_TEXT)) {
+			switch (keycode) {
+				case WKC_UP:
+					this->SelectPreviousSign();
+					state = ES_HANDLED;
+					break;
+
+				case WKC_DOWN:
+					this->SelectNextSign();
+					state = ES_HANDLED;
+			}
+		}
+
+		return state;
+	}
+
+	virtual void OnOSKInput(int widget)
+	{
+		if (widget == SLW_FILTER_TEXT) this->SetFilterString(this->text.buf);
+	}
+
+	virtual void OnMouseLoop()
+	{
+		this->HandleEditBox(SLW_FILTER_TEXT);
+ 	}
+
 	virtual void OnResize()
 	{
 		this->vscroll.SetCapacityFromWidget(this, SLW_LIST, WD_FRAMERECT_TOP + WD_FRAMERECT_BOTTOM);
@@ -208,9 +429,14 @@
 							SetResize(1, 10), SetFill(1, 0), EndContainer(),
 		NWidget(NWID_VERTICAL),
 			NWidget(WWT_SCROLLBAR, COLOUR_GREY, SLW_SCROLLBAR),
-			NWidget(WWT_RESIZEBOX, COLOUR_GREY),
 		EndContainer(),
 	EndContainer(),
+	NWidget(NWID_HORIZONTAL),
+		NWidget(WWT_EDITBOX, COLOUR_GREY, SLW_FILTER_TEXT), SetMinimalSize(80, 12), SetResize(1, 0), SetFill(1, 0),
+		NWidget(WWT_PUSHTXTBTN, COLOUR_GREY, SLW_FILTER_MATCH_CASE_BTN), SetDataTip(STR_FILTER_MATCH_CASE, STR_NULL),
+		NWidget(WWT_PUSHTXTBTN, COLOUR_GREY, SLW_FILTER_CLEAR_BTN), SetDataTip(STR_FILTER_CLEAR, STR_NULL),
+		NWidget(WWT_RESIZEBOX, COLOUR_GREY),
+	EndContainer(),
 };
 
 static const WindowDesc _sign_list_desc(
Index: src/toolbar_gui.cpp
===================================================================
--- src/toolbar_gui.cpp	(revision 18696)
+++ src/toolbar_gui.cpp	(working copy)
@@ -1279,6 +1279,7 @@
 			case WKC_CTRL  | 'S': MenuClickSmallScreenshot(); break;
 			case WKC_CTRL  | 'G': MenuClickWorldScreenshot(); break;
 			case WKC_CTRL | WKC_ALT | 'C': if (!_networking) ShowCheatWindow(); break;
+			case WKC_CTRL | 'L': ShowSignList(); break;
 			case 'A': if (CanBuildVehicleInfrastructure(VEH_TRAIN)) ShowBuildRailToolbar(_last_built_railtype, 4); break; // Invoke Autorail
 			case 'L': ShowTerraformToolbar(); break;
 			case 'Q': case 'W': case 'E': case 'D': ShowTerraformToolbarWithTool(key, keycode); break;