| Interface | Description |
| Cloner<T> | Supports cloning, which creates a new instance of a class with the same value as an existing instance. |
| IAboveAverage | Represents an above average visual of a conditional formatting rule. |
| IAlternatingStyles | Represents a collection of alternating styles. |
| IAreas | Represents a collection of the areas, or contiguous blocks of cells, within a selection. |
| IArray<T> | Represents an array of items which are declared as type. |
| IAuthor | Represents the author of the ICommentThreaded object. |
| IAutoFilter | Represents the filter for the specified worksheet. |
| IAutoFilterOwner | Represents an object which contains an AutoFilter. |
| IBorder | Represents the border of an object. |
| IBorders | A collection of Border objects that represent the four borders of a Range or Style object. |
| ICellType | Represents the cell type of a cell. |
| ICharacters | Represents characters in an object that contains text. |
| IColorPalette | Represents the color palette that contains indexed colors. |
| IColorScale | |
| IColorScaleCriteria | A collection of ColorScaleCriterion objects that represents all of the criteria for a color scale conditional format. Each criterion specifies the minimum, midpoint, or maximum threshold for the color scale. |
| IColorScaleCriterion | Represents the criteria for the minimum, midpoint, or maximum thresholds for a color format conditional format. |
| IColorStops | A collection of all the ColorStop objects for the specified series. |
| IColumnFooter | Represents the column footer of a worksheet. |
| IColumnHeader | Represents the column header of a worksheet. |
| IComment | Represents a cell comment. |
| IComments | Represents a collection of cell comments. |
| ICommentsThreaded | Represents a collection of top-level ICommentThreaded objects in a worksheet, or a collection of replies in a single threaded comment. |
| ICommentThreaded | Represents a cell's threaded comment. This object can represent both a top-level comment or its replies. |
| ICompositeExtendData | Represents an interface for other products to extend composable data of Worksheet. |
| IConditionValue | Represents how the shortest bar or longest bar is evaluated for a data bar conditional formatting rule. |
| IDatabar | Represents a data bar conditional formating rule. |
| IDatabarBorder | Represents the border of the data bars specified by a conditional formatting rule. |
| IDataManager | Represents the data manager of a worksheet. |
| IEditor | Represents the editor of a cell. |
| IExtendedData | Represents an interface for other products to extend data of Worksheet. |
| IFilter | Represents a filter for a single column. |
| IFilters | Represents a collection of IFilter objects that represents all the filters in an auto filtered range. |
| IFont | Contains the font attributes (font name, font size, color, and so on) for an object. |
| IFormatCondition | Represents a conditional format. |
| IFormatConditions | Represents the collection of conditional formats for a single range. |
| IFormatter | Represents the value formatter. |
| IGradient | Contains the font attributes (font name, font size, color, and so on) for an object. |
| IGraphic | Contains properties that apply to header and footer picture objects. |
| IHyperlink | Represents a hyperlink. |
| IHyperlinks | Represents the collection of hyperlinks for a worksheet or range. |
| IIconCriteria | Represents the collection of IconCriterion objects. Each IconCriterion represents the values and threshold type for each icon in an icon set conditional formatting rule. |
| IIconCriterion | Represents the criterion for an individual icon in an icon set. The criterion specifies the range of values and the threshold type associated with the icon in an icon set conditional formatting rule. |
| IIconSetCondition | Represents an icon set conditional formatting rule. |
| IInterior | Represents the interior of an object. |
| IMedia | Represents an embedded resource. |
| IName | Represents a defined name. |
| INames | Represents a collection of all the IName objects in the workbook. |
| INegativeBarFormat | Represents the color settings of the data bars for negative values that are defined by a data bar conditional formating rule. |
| INumberFormatExtendData | Represents extend data for NumberFormat. |
| IOutline | Represents an outline on a worksheet. |
| IRange | Interface that represent a range of a worksheet. |
| IReadonlyArray<T> | Represents a read-only array of items which are declared as type. |
| IRowHeader | Represents the row header of a worksheet. |
| ISort | Represents a sort of a range of data. |
| ISortComparer | Represents a custom sort comparer. |
| ISortField | Represent an object contains all the sort information for the IWorksheet, ITable, and IAutoFilter objects. |
| ISortFields | Represents the collection of ISortField objects. |
| ISparkAxes | Represents the settings for the horizontal and vertical axes of a group of sparklines. |
| ISparkColor | Represents the color of the horizontal axis and the markers for points in a sparkline. |
| ISparkHorizontalAxis | Represents the settings for the horizontal axes of a group of sparklines. |
| ISparkline | Represents a single sparkline. |
| ISparklineGroup | Represents a group of sparklines. |
| ISparklineGroups | Represents a collection of sparkline groups. |
| ISparkPoints | Represents the settings of the markers for points of data on a sparkline. |
| ISparkVerticalAxis | Represents the settings for the vertical axes of a group of sparklines. |
| ISpreadsheet | Represent an absract spreadsheet. |
| IStyle | Represents the appearance of the cells in the worksheet. |
| IStyles | Represents a collection of all styles in the workbook. |
| ITable | Represents a table of the worksheet. |
| ITableColumn | Represents a column in a table. |
| ITableColumns | Represents a collection of all the ITableColumn objects in the specified ITable object. |
| ITableRow | Represents a row in a table. |
| ITableRows | Represents a collection of all the table rows in the specified table. |
| ITables | Represents an ITables object which manages all ITable tables in the specified IWorksheet. |
| ITableStyle | Represents a single style that can be applied to a table. |
| ITableStyleElement | Represents a single table style element. |
| ITableStyleElements | Represents table style elements. |
| ITableStyles | Represents styles that can be applied to a table. |
| ITop10 | Represents a top ten visual of a conditional formatting rule. Applying a color to a range helps you see the value of a cell relative to other cells. |
| IUniqueValues | The UniqueValues object uses the DupeUnique property to Gets or sets an enum that determines whether the rule should look for duplicate or unique values in the range. |
| IValidation | Represents data validation for a worksheet range. |
| IWorkbook | Represents a workbook. |
| IWorkbooks | Represents a set of workbooks in a workbook set. |
| IWorkbookSet | Represents a set of workbooks which may refer to each other by external cell references or external defined name references. |
| IWorksheet | Represents a worksheet. |
| IWorksheets | Represents a set of worksheets in a workbook. |
| IWorksheetStyles | Represents a collection of all styles in the worksheet. |
| IWorksheetView | Represents a worksheet view. |
| NamedObjectCollection.IContainer<TItem,TContainer> | Represents the container which contains this NamedObjectCollection<TItem,TContainer> collection. |
| NamedObjectCollection.IItem<TItem,TContainer> | Represents the type of elements in this NamedObjectCollection<TItem,TContainer> collection. |