| QCPAbstractItem | The abstract base class for all items in a plot |
| QCPAbstractLegendItem | The abstract base class for all items in a QCPLegend |
| QCPAbstractPlottable | The abstract base class for all data representing objects in a plot |
| QCPAxis | Manages a single axis inside a QCustomPlot |
| QCPBarData | Holds the data of one single data point (one bar) for QCPBars |
| QCPBars | A plottable representing a bar chart in a plot |
| QCPCurve | A plottable representing a parametric curve in a plot |
| QCPCurveData | Holds the data of one single data point for QCPCurve |
| QCPData | Holds the data of one single data point for QCPGraph |
| QCPGraph | A plottable representing a graph in a plot |
| QCPGrid | Responsible for drawing the grid of a QCPAxis |
| QCPItemAnchor | An anchor of an item to which positions can be attached to |
| 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 |
| QCPItemPosition | Manages the position of an item |
| 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 |
| QCPLayer | A layer that may contain objects, to control the rendering order |
| QCPLayerable | Base class for all objects that can be placed on layers |
| QCPLegend | Manages a legend inside a QCustomPlot |
| QCPLineEnding | Handles the different ending decorations for line-like items |
| QCPPainter | QPainter subclass used internally |
| QCPPlottableLegendItem | A legend item representing a plottable with an icon and the plottable name |
| QCPRange | Represents the range an axis is encompassing |
| QCPStatisticalBox | A plottable representing a single statistical box in a plot |
| QCustomPlot | The central class of the library, the QWidget which displays the plot and interacts with the user |