Yes, you can convert an OLM file to PST without installing Outlook. Consider a simple situation: someone has an OLM file from an old Outlook for Mac account, but the Mac computer is no longer being used. The OLM file contains important business emails and attachments, and the user wants to save the data as a PST file. Installing Outlook again may not always be practical. In such a case, an OLM converter that can independently parse the OLM file can be used.

The MacSonik OLM Converter is designed for this type of conversion. The provided content states that its proprietary OLM parsing engine can open and read OLM files without Outlook for Mac. This means the software works directly with the OLM database instead of relying on an installed Outlook application. Users can select the OLM file, preview the available mailbox data, and export it to PST along with other supported formats.
Read more: https://www.macsonik.com/olm/converter/