diff --git a/homeassistant/components/transmission/const.py b/homeassistant/components/transmission/const.py
index 517ef0a853a..0e29bbbff5f 100644
--- a/homeassistant/components/transmission/const.py
+++ b/homeassistant/components/transmission/const.py
@@ -10,9 +10,9 @@ ORDER_WORST_RATIO_FIRST = "worst_ratio_first"
 
 SUPPORTED_ORDER_MODES = {
     ORDER_NEWEST_FIRST: lambda torrents: sorted(
-        torrents, key=lambda t: t.addedDate, reverse=True
+        torrents, key=lambda t: t.date_added, reverse=True
     ),
-    ORDER_OLDEST_FIRST: lambda torrents: sorted(torrents, key=lambda t: t.addedDate),
+    ORDER_OLDEST_FIRST: lambda torrents: sorted(torrents, key=lambda t: t.date_added),
     ORDER_WORST_RATIO_FIRST: lambda torrents: sorted(torrents, key=lambda t: t.ratio),
     ORDER_BEST_RATIO_FIRST: lambda torrents: sorted(
         torrents, key=lambda t: t.ratio, reverse=True
diff --git a/homeassistant/components/transmission/manifest.json b/homeassistant/components/transmission/manifest.json
index 53441057a5c..17b3bbbf49b 100644
--- a/homeassistant/components/transmission/manifest.json
+++ b/homeassistant/components/transmission/manifest.json
@@ -6,5 +6,5 @@
   "documentation": "https://www.home-assistant.io/integrations/transmission",
   "iot_class": "local_polling",
   "loggers": ["transmissionrpc"],
-  "requirements": ["transmission-rpc==3.4.0"]
+  "requirements": ["transmission-rpc==4.1.5"]
 }
diff --git a/homeassistant/components/transmission/sensor.py b/homeassistant/components/transmission/sensor.py
index 2c7bf24cdfd..184d05faeb0 100644
--- a/homeassistant/components/transmission/sensor.py
+++ b/homeassistant/components/transmission/sensor.py
@@ -117,9 +117,9 @@ class TransmissionSpeedSensor(TransmissionSensor):
         """Get the latest data from Transmission and updates the state."""
         if data := self._tm_client.api.data:
             b_spd = (
-                float(data.downloadSpeed)
+                float(data.download_speed)
                 if self._sub_type == "download"
-                else float(data.uploadSpeed)
+                else float(data.upload_speed)
             )
             self._state = b_spd
 
@@ -134,8 +134,8 @@ class TransmissionStatusSensor(TransmissionSensor):
     def update(self) -> None:
         """Get the latest data from Transmission and updates the state."""
         if data := self._tm_client.api.data:
-            upload = data.uploadSpeed
-            download = data.downloadSpeed
+            upload = data.upload_speed
+            download = data.download_speed
             if upload > 0 and download > 0:
                 self._state = STATE_UP_DOWN
             elif upload > 0 and download == 0:
@@ -199,8 +199,8 @@ def _torrents_info(torrents, order, limit, statuses=None):
     torrents = SUPPORTED_ORDER_MODES[order](torrents)
     for torrent in torrents[:limit]:
         info = infos[torrent.name] = {
-            "added_date": torrent.addedDate,
-            "percent_done": f"{torrent.percentDone * 100:.2f}",
+            "added_date": torrent.date_added,
+            "percent_done": f"{torrent.percent_done * 100:.2f}",
             "status": torrent.status,
             "id": torrent.id,
         }
diff --git a/homeassistant/components/transmission/switch.py b/homeassistant/components/transmission/switch.py
index ed771d24581..3af3fe57e3c 100644
--- a/homeassistant/components/transmission/switch.py
+++ b/homeassistant/components/transmission/switch.py
@@ -118,7 +118,7 @@ class TransmissionSwitch(SwitchEntity):
         if self.type == "on_off":
             self._data = self._tm_client.api.data
             if self._data:
-                active = self._data.activeTorrentCount > 0
+                active = self._data.active_torrent_count > 0
 
         elif self.type == "turtle_mode":
             active = self._tm_client.api.get_alt_speed_enabled()
diff --git a/requirements_all.txt b/requirements_all.txt
index 0cd876ccfb9..22e670a8436 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -2521,7 +2521,7 @@ tp-connected==0.0.4
 tplink-omada-client==1.1.4
 
 # homeassistant.components.transmission
-transmission-rpc==3.4.0
+transmission-rpc==4.1.5
 
 # homeassistant.components.twinkly
 ttls==1.5.1
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index 3b2e98ceae3..bf40b7136ed 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -1797,7 +1797,7 @@ total_connect_client==2023.2
 tplink-omada-client==1.1.4
 
 # homeassistant.components.transmission
-transmission-rpc==3.4.0
+transmission-rpc==4.1.5
 
 # homeassistant.components.twinkly
 ttls==1.5.1