diff --git a/client/project.godot b/client/project.godot
index 8aa99cf2f..479146b4c 100644
--- a/client/project.godot
+++ b/client/project.godot
@@ -125,6 +125,11 @@ debug_overlay={
 "events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":4194334,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
 ]
 }
+open_journal={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":74,"key_label":0,"unicode":106,"location":0,"echo":false,"script":null)
+]
+}
 teleport_hub={
 "deadzone": 0.5,
 "events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":4194317,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
diff --git a/client/scripts/autoloads/input_mapper.gd b/client/scripts/autoloads/input_mapper.gd
index 9a51eee07..37957efd0 100644
--- a/client/scripts/autoloads/input_mapper.gd
+++ b/client/scripts/autoloads/input_mapper.gd
@@ -19,6 +19,7 @@ enum Action {
 	INTERACT, USE_PERCEPTION_MODE, OPEN_MENU, PAUSE, UNPAUSE,
 	TOGGLE_STANCE_UP, TOGGLE_STANCE_DOWN,
 	BUG_REPORT,  # #495: F12 WRONG button — client-only, not sent to server
+	OPEN_JOURNAL,  # #264: J key — toggle knowledge journal panel, client-only
 	SET_FACING,  # D-054: facing octant update (no movement)
 	TELEPORT_HUB,  # #501: Home key — Gauntlet dev teleport (not production fast-travel)
 }
@@ -106,6 +107,8 @@ func _unhandled_input(event: InputEvent) -> void:
 		action = Action.TOGGLE_STANCE_DOWN
 	elif event.is_action_pressed("bug_report"):
 		action = Action.BUG_REPORT
+	elif event.is_action_pressed("open_journal"):
+		action = Action.OPEN_JOURNAL
 	elif event.is_action_pressed("teleport_hub"):
 		if GameState.gauntlet_mode:
 			action = Action.TELEPORT_HUB
diff --git a/client/ui/journal_panel.gd b/client/ui/journal_panel.gd
new file mode 100644
index 000000000..2f39ee02e
--- /dev/null
+++ b/client/ui/journal_panel.gd
@@ -0,0 +1,194 @@
+extends Control
+
+## Journal panel — knowledge graph review. #264, D-041.
+##
+## Toggle with J key. Displays accumulated facts from GameState.player_knowledge
+## grouped by entity. Read-only — no player interaction beyond scrolling.
+##
+## KnowledgeState rendering:
+##   Active       → normal color (INSERT_COLOR_TEXT)
+##   Stale        → dimmed (IMPLANT_TEXT_DIM)
+##   Contradicted → amber tint + strikethrough (ENTITY_COLOR_POI) — THE FRIEND arc surface
+##
+## KnowledgeConfidence labels (D-041):
+##   Direct → KnowsDetails → KnowsOf → Suspects
+##
+## Cannot be open simultaneously with dialogue (sprint briefing constraint).
+## Closes when dialogue opens.
+
+const FADE_IN: float = 0.18
+const FADE_OUT: float = 0.25
+
+# D-041 confidence → display label
+const CONFIDENCE_LABELS: Dictionary = {
+	"Direct": "Confirmed",
+	"KnowsDetails": "Detailed",
+	"KnowsOf": "Known",
+	"Suspects": "Unconfirmed",
+}
+
+# D-041 source → display label
+const SOURCE_LABELS: Dictionary = {
+	"DirectObservation": "Observed",
+	"ToldBy": "Told",
+	"Heard": "Overheard",
+	"Inferred": "Inferred",
+	"Background": "Prior",
+}
+
+@onready var panel: PanelContainer = $PanelContainer
+@onready var title_label: Label = $PanelContainer/MarginContainer/VBoxContainer/TitleLabel
+@onready var scroll: ScrollContainer = $PanelContainer/MarginContainer/VBoxContainer/ScrollContainer
+@onready var entries_container: VBoxContainer = $PanelContainer/MarginContainer/VBoxContainer/ScrollContainer/EntriesContainer
+
+var _visible_state: bool = false
+var _last_rendered_tick: int = -1
+
+func _ready() -> void:
+	mouse_filter = Control.MOUSE_FILTER_IGNORE
+	visible = false
+	modulate.a = 0.0
+	title_label.text = UIStrings.get_text("knowledge_panel.tab_contacts")
+
+
+## Toggle open/close. Called from main.gd on J key press.
+func toggle() -> void:
+	if _visible_state:
+		_hide_panel()
+	else:
+		_show_panel()
+
+
+## Force-close. Called when dialogue opens.
+func close() -> void:
+	if _visible_state:
+		_hide_panel()
+
+
+func is_open() -> bool:
+	return _visible_state
+
+
+func _show_panel() -> void:
+	_rebuild_entries()
+	_visible_state = true
+	visible = true
+	var t := create_tween()
+	t.tween_property(self, "modulate:a", 1.0, FADE_IN)
+
+
+func _hide_panel() -> void:
+	_visible_state = false
+	var t := create_tween()
+	t.tween_property(self, "modulate:a", 0.0, FADE_OUT)
+	t.tween_callback(func(): visible = false)
+
+
+## Rebuild the entry list from GameState.player_knowledge.
+func _rebuild_entries() -> void:
+	# Clear previous entries
+	for child in entries_container.get_children():
+		child.queue_free()
+
+	var knowledge: Variant = GameState.player_knowledge
+	if knowledge == null:
+		_add_empty_state()
+		return
+
+	var entities: Array = knowledge.get("entities", [])
+	if entities.is_empty():
+		_add_empty_state()
+		return
+
+	for entity in entities:
+		if not entity is Dictionary:
+			continue
+		_add_entity_entry(entity)
+
+
+func _add_empty_state() -> void:
+	var label := Label.new()
+	label.text = UIStrings.get_text("knowledge_panel.empty_state")
+	label.add_theme_color_override("font_color", Constants.IMPLANT_TEXT_DIM)
+	label.add_theme_font_size_override("font_size", 13)
+	entries_container.add_child(label)
+
+
+func _add_entity_entry(entity: Dictionary) -> void:
+	var name_str: String = entity.get("name", "Unknown")
+	var confidence: String = entity.get("confidence", "Suspects")
+	var source: String = entity.get("source", "")
+	var state: String = entity.get("state", "Active")
+	var relationship: String = entity.get("relationship", "Unknown")
+
+	# Entity header — name + relationship status
+	var header_rtl := RichTextLabel.new()
+	header_rtl.bbcode_enabled = true
+	header_rtl.fit_content = true
+	header_rtl.scroll_active = false
+	header_rtl.mouse_filter = Control.MOUSE_FILTER_IGNORE
+	header_rtl.add_theme_font_size_override("normal_font_size", 14)
+
+	var rel_color: Color = Constants.color_for_relationship(relationship)
+	var rel_label: String = UIStrings.get_text("relationship_states.%s.label" % relationship.to_lower())
+	if rel_label == "relationship_states.%s.label" % relationship.to_lower():
+		rel_label = relationship  # fallback if key missing
+
+	var state_color: Color = _state_color(state)
+	var conf_label: String = CONFIDENCE_LABELS.get(confidence, confidence)
+	var src_label: String = SOURCE_LABELS.get(source, source)
+
+	# Build BBCode:
+	# [color=#hex][b]Name[/b][/color]  [color=#rel_hex]Status[/color]
+	var name_hex: String = state_color.to_html(false)
+	var rel_hex: String = rel_color.to_html(false)
+
+	var header_bbcode: String
+	if state == "Contradicted":
+		header_bbcode = "[color=#%s][b][s]%s[/s][/b][/color]  [color=#%s]%s[/color]" % [
+			name_hex, name_str, rel_hex, rel_label
+		]
+	else:
+		header_bbcode = "[color=#%s][b]%s[/b][/color]  [color=#%s]%s[/color]" % [
+			name_hex, name_str, rel_hex, rel_label
+		]
+	header_rtl.text = header_bbcode
+	entries_container.add_child(header_rtl)
+
+	# Detail line — confidence + source
+	var detail_rtl := RichTextLabel.new()
+	detail_rtl.bbcode_enabled = true
+	detail_rtl.fit_content = true
+	detail_rtl.scroll_active = false
+	detail_rtl.mouse_filter = Control.MOUSE_FILTER_IGNORE
+	detail_rtl.add_theme_font_size_override("normal_font_size", 12)
+
+	var detail_hex: String = Constants.IMPLANT_TEXT_DIM.to_html(false)
+	var detail_text: String = "%s · %s" % [conf_label, src_label] if src_label else conf_label
+	detail_rtl.text = "[color=#%s]%s[/color]" % [detail_hex, detail_text]
+	entries_container.add_child(detail_rtl)
+
+	# Spacer between entries
+	var spacer := Control.new()
+	spacer.custom_minimum_size = Vector2(0, 6)
+	entries_container.add_child(spacer)
+
+
+func _state_color(state: String) -> Color:
+	match state:
+		"Contradicted":
+			return Constants.ENTITY_COLOR_POI   # amber — THE FRIEND arc
+		"Stale":
+			return Constants.IMPLANT_TEXT_DIM   # dimmed
+		_:
+			return Constants.INSERT_COLOR_TEXT  # active — normal
+
+
+## Called from main.gd on each snapshot to close the panel when dialogue opens.
+func update_from_state() -> void:
+	if _visible_state and GameState.dialogue_active:
+		close()
+	# Rebuild if open and knowledge data is newer than last render
+	if _visible_state and GameState.current_tick != _last_rendered_tick:
+		_last_rendered_tick = GameState.current_tick
+		_rebuild_entries()
diff --git a/client/ui/journal_panel.tscn b/client/ui/journal_panel.tscn
new file mode 100644
index 000000000..9eedb4da9
--- /dev/null
+++ b/client/ui/journal_panel.tscn
@@ -0,0 +1,63 @@
+[gd_scene load_steps=2 format=3 uid="uid://journal_panel_sr"]
+
+[ext_resource type="Script" path="res://ui/journal_panel.gd" id="1_journal"]
+
+; JournalPanel — knowledge graph review. #264, D-041.
+; Toggle J key. Right side, 380px wide, full height minus margins.
+; InsertOverlay (CanvasLayer 10, z-layer 6). Read-only, closes with dialogue.
+
+[node name="JournalPanel" type="Control"]
+layout_mode = 3
+anchors_preset = 3
+anchor_left = 1.0
+anchor_top = 0.0
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = -400.0
+offset_top = 16.0
+offset_right = -16.0
+offset_bottom = -16.0
+grow_horizontal = 0
+grow_vertical = 2
+mouse_filter = 2
+modulate = Color(1, 1, 1, 0)
+script = ExtResource("1_journal")
+
+[node name="PanelContainer" type="PanelContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+mouse_filter = 2
+
+[node name="MarginContainer" type="MarginContainer" parent="PanelContainer"]
+layout_mode = 2
+theme_override_constants/margin_left = 14
+theme_override_constants/margin_top = 12
+theme_override_constants/margin_right = 14
+theme_override_constants/margin_bottom = 12
+
+[node name="VBoxContainer" type="VBoxContainer" parent="PanelContainer/MarginContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="TitleLabel" type="Label" parent="PanelContainer/MarginContainer/VBoxContainer"]
+layout_mode = 2
+text = "Contacts"
+theme_override_font_sizes/font_size = 15
+theme_override_colors/font_color = Color(0.784, 0.816, 0.878, 0.9)
+
+[node name="Separator" type="HSeparator" parent="PanelContainer/MarginContainer/VBoxContainer"]
+layout_mode = 2
+theme_override_colors/separator_color = Color(0.784, 0.816, 0.878, 0.2)
+
+[node name="ScrollContainer" type="ScrollContainer" parent="PanelContainer/MarginContainer/VBoxContainer"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="EntriesContainer" type="VBoxContainer" parent="PanelContainer/MarginContainer/VBoxContainer/ScrollContainer"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 2