  QCPBarData | Holds the data of one single data point (one bar) for QCPBars |
| QCPBarsGroup | Groups multiple QCPBars together so they appear side by side |
| QCPColorGradient | Defines a color gradient for use with e.g. QCPColorMap |
| QCPColorMapData | Holds the two-dimensional data of a QCPColorMap plottable |
| QCPCurveData | Holds the data of one single data point for QCPCurve |
| QCPData | Holds the data of one single data point for QCPGraph |
| QCPFinancialData | Holds the data of one single data point for QCPFinancial |
 QCPItemAnchor | An anchor of an item to which positions can be attached to |
  QCPItemPosition | Manages the position of an item |
| QCPLayer | A layer that may contain objects, to control the rendering order |
| QCPLayerable | Base class for all drawable objects |
| QCPAbstractItem | The abstract base class for all items in a plot |
| QCPItemBracket | A bracket for referencing/highlighting certain parts in the plot |
| QCPItemCurve | A curved line from one point to another |
| QCPItemEllipse | An ellipse |
| QCPItemLine | A line from one point to another |
| QCPItemPixmap | An arbitrary pixmap |
| QCPItemRect | A rectangle |
| QCPItemStraightLine | A straight line that spans infinitely in both directions |
| QCPItemText | A text label |
| QCPItemTracer | Item that sticks to QCPGraph data points |
| QCPAbstractPlottable | The abstract base class for all data representing objects in a plot |
| QCPBars | A plottable representing a bar chart in a plot |
| QCPColorMap | A plottable representing a two-dimensional color map in a plot |
| QCPCurve | A plottable representing a parametric curve in a plot |
| QCPFinancial | A plottable representing a financial stock chart |
| QCPGraph | A plottable representing a graph in a plot |
| QCPStatisticalBox | A plottable representing a single statistical box in a plot |
| QCPAxis | Manages a single axis inside a QCustomPlot |
| QCPGrid | Responsible for drawing the grid of a QCPAxis |
 QCPLayoutElement | The abstract base class for all objects that form the layout system |
 QCPAbstractLegendItem | The abstract base class for all entries in a QCPLegend |
| QCPPlottableLegendItem | A legend item representing a plottable with an icon and the plottable name |
| QCPAxisRect | Holds multiple axes and arranges them in a rectangular shape |
| QCPColorScale | A color scale for use with color coding data such as QCPColorMap |
| QCPLayout | The abstract base class for layouts |
| QCPLayoutGrid | A layout that arranges child elements in a grid |
| QCPLegend | Manages a legend inside a QCustomPlot |
| QCPLayoutInset | A layout that places child elements aligned to the border or arbitrarily positioned |
| QCPPlotTitle | A layout element displaying a plot title text |
| QCPLineEnding | Handles the different ending decorations for line-like items |
| QCPMarginGroup | A margin group allows synchronization of margin sides if working with multiple layout elements |
| QCPPainter | QPainter subclass used internally |
| QCPRange | Represents the range an axis is encompassing |
| QCPScatterStyle | Represents the visual appearance of scatter points |
| QCustomPlot | The central class of the library. This is the QWidget which displays the plot and interacts with the user |