| OLAP Cube Wizard |
| OLAP Cubes |
| OLAP Pivot Charts |
| OLE (Object Linking and Embedding) |
| OLE Objects |
| Omits Adjacent Cells |
| Omits Cells in Region |
| OMPM (Office Migration Planning Manager) |
| OnCalculate |
| OnChange Event |
| One Dimensional Arrays |
| One Variable Data Table |
| OnEntry |
| On-Line Analytical Processing (OLAP) |
| Online Collaboration |
| Only Updates Formula After Saving |
| Open and Repair |
| Open At Startup |
| Open Database Connectivity (ODBC) Add-in |
| Open Dialog Box |
| Open File in New Window |
| Open Hyperlink |
| Open Office XML Format |
| Open Several Workbooks |
| Open Two Workbooks Same Time |
| Open Workbook Windows |
| Open XML Format |
| OpenDocument Spreadsheet |
| Opening Add-ins |
| Opening Excel holding down Ctrl |
| Opening Excel Startup Switches |
| Opening Files Automatically |
| Opening Multiple Workbooks |
| Opening SharePoint Workbooks |
| Opening Workbook holding down Shift |
| Opening Workbooks |
| Opening Workbooks - Calculation |
| Opening Workbooks - Protected View |
| Opening Workbooks - Security Alert |
| Opening Workbooks with Links |
| Operators |
| Operators - Formulas |
| Operis Add-in |
| Operis Add-in - OAK |
| Operis Analysis Kit (OAK) |
| Optimal Print Range |
| Optimisation Analysis |
| Option Button |
| OptionButton - Controls |
| Options |
| Options - Add-ins |
| Options - Advanced |
| Options - Ask Before Updating Links |
| Options - Calculate Before Saving |
| Options - Calculate on Close |
| Options - Calculate on Open |
| Options - Calculate on Save |
| Options - Compress Images |
| Options - Customize Ribbon |
| Options - FAQs |
| Options - Formulas |
| Options - General |
| Options - Language |
| Options - Proofing |
| Options - Quick Access Toolbar |
| Options - Save |
| Options - Threading |
| Options - Trust Center |
| Options - Workbook Specific |
| Options - Worksheet Specific |
| OR - Built-in Function |
| Order of Operations - Formulas |
| ORDINAL - User Defined Function |
| Organisation Charts |
| Orientation - Charts |
| Orientation - Formatting |
| Orientation - Landscape |
| Orientation - Page Setup |
| Orientation - Portrait |
| Orientation - Text |
| Orphan Links |
| Ounces |
| Outline Group |
| Outline Numbering |
| Outline Symbols |
| Outlines |
| Outlines - Automatic |
| Outlines - Grouping Data |
| Outlines - Subtotals |
| Outlines - Ungrouping Data |
| Outlining |
| Outlook Online Resource |
| Outlook Resource |
| Outside Borders |
| Override Formula |
| Overtype |
| Overtype Mode |
| OWC (Office Web Components) |