O File Extensions

File types with extensions that start with the letter O.

Extension	File Type	File Description
.o	Developer	Compiled Object File
.oab	Data	Offline Address Book
.oar	Compressed	OpenSimulator Archive
.ob!	Misc	Orbit Downloader Incomplete Download
.obi	Settings	Outlook RSS Subscription File
.obj	3D Image	3D Object File
.obj	Data	Relocatable Object Code
.obs	Executable	ObjectScript Script File
.oca	Developer	Custom Control Library Type File
.oce	Settings	Open Catalog Extension Connection File
.ocr	Text	FAXGrapper Fax Text File
.ocx	Developer	ActiveX Control
.odb	Data	ABAQUS Database
.odc	Image	OpenDocument Chart
.odf	Misc	OpenDocument Formula
.odf	Data	Open Document File
.odg	Image	OpenDocument Graphic
.odi	Image	OpenDocument Image
.odif	Image	Open Document Interchange Format
.odm	Text	OpenDocument Master Document
.odm	Audio	OverDrive Media File
.odp	Data	OpenDocument Presentation
.ods	Data	OpenDocument Spreadsheet
.ods	Misc	Outlook Express 5 Mailbox
.odt	Text	OpenDocument Text Document
.odx	Data	BizTalk Server Orchestration File
.oeaccount	Data	Windows Mail Account File
.oeb	Backup	Outlook Express Backup Wizard File
.oem	Settings	OEM Setup File
.ofc	Data	Open Financial Connectivity File
.off	Image	Object File Format
.ofl	Text	Ots File List
.ofm	Data	OmniForm Form
.oft	Data	Outlook File Template
.ofx	Data	Open Financial Exchange File
.oga	Audio	Ogg Vorbis Audio File
.ogg	Audio	Ogg Vorbis Compressed Audio File
.ogm	Video	Ogg Media File
.ognc	Web	Dynamic Web Page
.ogv	Video	Ogg Vorbis Video File
.ogx	Video	Ogg Vorbis Multiplexed Media File
.okt	Audio	Oktalyzer Module
.ola	Page Layout	Online Access File
.olb	Misc	OLE Object Library
.old	Backup	Backup File
.oma	Audio	Sony OpenMG Music File
.omcs	Data	Office Manager Access File
.omf	Audio	Open Media Framework File
.omf	Raster Image	OMF Interchange Image File
.omg	Audio	OpenMG Audio File
.omo	Developer	OMake Object File
.omp	Data	Office Manager Document Archive
.omx	Audio	OtsAV Media Library Information File
.ond	Data	Lotus Notes Encapsulated Memo File
.one	Data	OneNote Document
.onepkg	Backup	Microsoft OneNote Package File
.oo3	Data	OmniOutliner 3 File
.opd	Page Layout	OmniPage Document
.openbsd	Text	OpenBSD Readme File
.opf	Data	FlipViewer FlipBook File
.opf	Image	FlipAlbum File
.opml	Text	OPML File
.ops	Settings	Office Profile Settings File
.opt	Settings	Options File
.opx	Data	FlipAlbum Photo Album File
.opx	Data	OrgPlus Org Chart
.or2	Data	Lotus Organizer 2 File
.or3	Data	IBM Lotus Organizer 97 File
.or4	Data	IBM Lotus Organizer 97 GS File
.or5	Data	Lotus Organizer 5 File
.or6	Data	Lotus Organizer 6 File
.orf	Raster Image	Olympus RAW File
.org	Data	Lotus Organizer File
.ori	Backup	Original File
.ort	Text	Rich Text Editor Document
.orx	Data	RadiantOne VDS Database Schema
.ost	Misc	Outlook Offline Folder File
.osx	Executable	PowerPC Executable File
.osz	Game	Osu! Beatmap File
.ota	Image	OTA Bitmap
.otb	Image	Nokia Over The Air Bitmap
.otc	Image	OpenDocument Chart Template
.otf	Misc	OpenDocument Formula Template
.otf	Data	OpenTuft Tufting Design File
.otf	Font	OpenType Font
.otg	Image	OpenDocument Graphic Template
.oth	Web	OpenDocument HTML Template
.oti	Image	OpenDocument Image Template
.otl	Data	NoteTab Outline File
.otln	Data	Opal Outline File
.otp	Misc	OpenDocument Presentation Template
.ots	Audio	OtsAV Album File
.ots	Data	OpenDocument Spreadsheet Template
.ott	Text	OpenDocument Text Document Template
.out	Data	Output File
.ov2	Data	TomTom Points of Interest Database
.ova	Data	Open Virtual Appliance
.ova	Data	Octava Musical Score
.ove	Audio	Overture Musical Score
.ovf	Data	Open Virtualization File
.ovl	Game	Rollercoaster Tycoon 3 Sprites File
.ovpn	Settings	OpenVPN Configuration File
.ovw	Image	Cubase WAVE File Overview
.owc	Game	OutWit Catch Database
.owg	Misc	OutWit Gear Database
.owl	Developer	OWL Source Code File
.owm	Misc	OutWit XML Mashup File
.oxt	Plugin	OpenOffice.org Extension
.oyx	Backup	Approach Alternate Database Index