| OCT2BIN* | The number converted from octal to a binary. |
| OCT2DEC* | The number converted from octal to decimal. |
| OCT2HEX* | The number converted from octal to hexadecimal. |
| ODD | The number rounded up to the nearest odd integer. |
| ODDFPRICE* | The price per $100 face value of a security with an odd first period. |
| ODDFYIELD* | The yield of a security with an odd first period. |
| ODDLPRICE* | The price per $100 face value of a security with an odd last period. |
| ODDLYIELD* | The yield of a security with an odd last period. |
| OFFSET | The cell value which is an offset from a given cell reference. |
| OR | The logical OR for any number of arguments. |
