diff --git a/Doxyfile b/Doxyfile
index a19120b9d..503979b61 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -48,7 +48,7 @@ PROJECT_NAME           = ESPHome
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2025.12.0-dev
+PROJECT_NUMBER         = 2026.1.0-dev
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
diff --git a/esphome/const.py b/esphome/const.py
index 8fa2d8da1..c94ead0be 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -4,7 +4,7 @@ from enum import Enum
 
 from esphome.enum import StrEnum
 
-__version__ = "2025.12.0-dev"
+__version__ = "2026.1.0-dev"
 
 ALLOWED_NAME_CHARS = "abcdefghijklmnopqrstuvwxyz0123456789-_"
 VALID_SUBSTITUTIONS_CHARACTERS = (