diff --git a/esphome/components/i2s_audio/__init__.py b/esphome/components/i2s_audio/__init__.py
index 3d5ec97a633..4abc807ee3d 100644
--- a/esphome/components/i2s_audio/__init__.py
+++ b/esphome/components/i2s_audio/__init__.py
@@ -17,6 +17,7 @@ from esphome.components.esp32.const import (
     VARIANT_ESP32P4,
     VARIANT_ESP32S2,
     VARIANT_ESP32S3,
+    VARIANT_ESP32S31,
 )
 from esphome.components.microphone import DOMAIN as MICROPHONE_DOMAIN
 from esphome.config_helpers import filter_source_files_from_defines
@@ -98,6 +99,7 @@ I2S_PORTS = {
     VARIANT_ESP32P4: 3,
     VARIANT_ESP32S2: 1,
     VARIANT_ESP32S3: 2,
+    VARIANT_ESP32S31: 2,
 }
 
 i2s_channel_fmt_t = cg.global_ns.enum("i2s_channel_fmt_t")
diff --git a/esphome/components/i2s_audio/microphone/__init__.py b/esphome/components/i2s_audio/microphone/__init__.py
index c2173172372..2ff709dbd1c 100644
--- a/esphome/components/i2s_audio/microphone/__init__.py
+++ b/esphome/components/i2s_audio/microphone/__init__.py
@@ -38,7 +38,12 @@ I2SAudioMicrophone = i2s_audio_ns.class_(
 )
 
 INTERNAL_ADC_VARIANTS = [esp32.VARIANT_ESP32]
-PDM_VARIANTS = [esp32.VARIANT_ESP32, esp32.VARIANT_ESP32S3, esp32.VARIANT_ESP32P4]
+PDM_VARIANTS = [
+    esp32.VARIANT_ESP32,
+    esp32.VARIANT_ESP32S3,
+    esp32.VARIANT_ESP32P4,
+    esp32.VARIANT_ESP32S31,
+]
 
 i2s_pdm_dsr_t = cg.global_ns.enum("i2s_pdm_dsr_t")
 I2S_PDM_DSR = {
diff --git a/tests/component_tests/i2s_audio/test_variants.py b/tests/component_tests/i2s_audio/test_variants.py
new file mode 100644
index 00000000000..3c5245565fa
--- /dev/null
+++ b/tests/component_tests/i2s_audio/test_variants.py
@@ -0,0 +1,68 @@
+"""Tests for the per-variant limits of i2s_audio: port count and PDM support."""
+
+import pytest
+
+from esphome import config_validation as cv
+from esphome.components import i2s_audio
+from esphome.components.esp32 import KEY_VARIANT
+from esphome.components.esp32.const import (
+    VARIANT_ESP32C3,
+    VARIANT_ESP32S2,
+    VARIANT_ESP32S31,
+)
+from esphome.components.i2s_audio import microphone
+from esphome.const import CONF_ID, PlatformFramework
+from esphome.core import ID
+from esphome.types import ConfigType
+from tests.component_tests.types import SetCoreConfigCallable
+
+CONF_FULL_DUPLEX = i2s_audio.CONF_FULL_DUPLEX
+
+
+def _set_variant(
+    set_core_config: SetCoreConfigCallable, variant: str, buses: int
+) -> None:
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_VARIANT: variant},
+        full_config={
+            i2s_audio.DOMAIN: [
+                {CONF_ID: ID(f"bus_{n}"), CONF_FULL_DUPLEX: False} for n in range(buses)
+            ]
+        },
+    )
+
+
+def test_esp32s31_has_two_i2s_ports(set_core_config: SetCoreConfigCallable) -> None:
+    _set_variant(set_core_config, VARIANT_ESP32S31, buses=2)
+    i2s_audio._final_validate({})
+
+
+def test_esp32s31_rejects_a_third_bus(set_core_config: SetCoreConfigCallable) -> None:
+    _set_variant(set_core_config, VARIANT_ESP32S31, buses=3)
+    with pytest.raises(cv.Invalid, match="Only 2 I2S audio ports"):
+        i2s_audio._final_validate({})
+
+
+def _pdm_microphone(pdm: bool) -> ConfigType:
+    return {
+        microphone.CONF_ADC_TYPE: "external",
+        microphone.CONF_PDM: pdm,
+    }
+
+
+def test_esp32s31_supports_pdm_microphones(
+    set_core_config: SetCoreConfigCallable,
+) -> None:
+    _set_variant(set_core_config, VARIANT_ESP32S31, buses=1)
+    microphone._validate_esp32_variant(_pdm_microphone(True))
+
+
+@pytest.mark.parametrize("variant", [VARIANT_ESP32S2, VARIANT_ESP32C3])
+def test_pdm_rejected_where_the_soc_has_none(
+    set_core_config: SetCoreConfigCallable, variant: str
+) -> None:
+    _set_variant(set_core_config, variant, buses=1)
+    with pytest.raises(cv.Invalid, match="does not support PDM"):
+        microphone._validate_esp32_variant(_pdm_microphone(True))
+    microphone._validate_esp32_variant(_pdm_microphone(False))
diff --git a/tests/components/i2s_audio/test.esp32-s31-idf.yaml b/tests/components/i2s_audio/test.esp32-s31-idf.yaml
new file mode 100644
index 00000000000..6457440bb4e
--- /dev/null
+++ b/tests/components/i2s_audio/test.esp32-s31-idf.yaml
@@ -0,0 +1,7 @@
+substitutions:
+  i2s_bclk_pin: GPIO5
+  i2s_lrclk_pin: GPIO4
+  i2s_mclk_pin: GPIO15
+
+packages:
+  i2s_audio: !include common.yaml
diff --git a/tests/components/microphone/test.esp32-s31-idf.yaml b/tests/components/microphone/test.esp32-s31-idf.yaml
new file mode 100644
index 00000000000..00f535b1692
--- /dev/null
+++ b/tests/components/microphone/test.esp32-s31-idf.yaml
@@ -0,0 +1,7 @@
+substitutions:
+  i2s_din_pin1: GPIO6
+  i2s_din_pin2: GPIO7
+
+packages:
+  i2s_audio: !include ../../test_build_components/common/i2s_audio/esp32-s31-idf.yaml
+  microphone: !include common-pdm.yaml
diff --git a/tests/components/speaker/test.esp32-s31-idf.yaml b/tests/components/speaker/test.esp32-s31-idf.yaml
new file mode 100644
index 00000000000..00a41ac969b
--- /dev/null
+++ b/tests/components/speaker/test.esp32-s31-idf.yaml
@@ -0,0 +1,7 @@
+substitutions:
+  i2s_dout_pin: GPIO10
+
+packages:
+  i2c: !include ../../test_build_components/common/i2c/esp32-s31-idf.yaml
+  i2s_audio: !include ../../test_build_components/common/i2s_audio/esp32-s31-idf.yaml
+  speaker: !include common.yaml