Office 2021
2024.4 the Office 2021 installation package in Windows includes the latest official version is OneNote 2021.
One-time Purchase Classic Office 2021 from Microsoft website:
https://www.microsoft.com/en-us/microsoft-365/p/office-home-student-2021/CFQ7TTC0H8N8?culture=en-us&country=US&activetab=pivot:overviewtab
Microsoft 365
Microsoft 365 includes the latest OneNote, so Microsoft 365 includes OneNote 2021.
Windows Office OneNote now has the following versions:
Note: The OneNote 2019 does not exist.
In 2018, OneNote was kicked out of Office 2019.
OneNote 2021 in Office 2021 LTSC Volumn License
OneNote 2021 in Retail Office 2021
OneNote 2021 in Microsoft 365