| QBitArray | Array of bits |
| QBitmap | Monochrome (1-bit depth) pixmaps |
| QBrush | Defines the fill pattern of shapes drawn by QPainter |
| QByteArray | Array of bytes |
| QCache | Template class that provides a cache |
| QContiguousCache | Template class that provides a contiguous cache |
| QCursor | Mouse cursor with an arbitrary shape |
| QDir | Access to directory structures and their contents |
| QFileInfo | System-independent file information |
| QFont | Specifies a font used for drawing text |
| QFontInfo | General information about fonts |
| QFontMetrics | Font metrics information |
| QFontMetricsF | Font metrics information |
| QGLColormap | Used for installing custom colormaps into a QGLWidget |
| QGradient | Used in combination with QBrush to specify gradient fills |
| QHash | Template class that provides a hash-table-based dictionary |
| QIcon | Scalable icons in different modes and states |
| QImage | Hardware-independent image representation that allows direct access to the pixel data, and can be used as a paint device |
| QKeySequence | Encapsulates a key sequence as used by shortcuts |
| QLinkedList | Template class that provides linked lists |
| QList | Template class that provides lists |
| QLocale | Converts between numbers and their string representations in various languages |
| QMap | Template class that provides a skip-list-based dictionary |
| QMultiHash | Convenience QHash subclass that provides multi-valued hashes |
| QMultiMap | Convenience QMap subclass that provides multi-valued maps |
| QPainterPath | Container for painting operations, enabling graphical shapes to be constructed and reused |
| QPalette | Contains color groups for each widget state |
| QPen | Defines how a QPainter should draw lines and outlines of shapes |
| QPicture | Paint device that records and replays QPainter commands |
| QPixmap | Off-screen image representation that can be used as a paint device |
| QPolygon | Vector of points using integer precision |
| QPolygonF | Vector of points using floating point precision |
| QQueue | Generic container that provides a queue |
| QRegExp | Pattern matching using regular expressions |
| QRegion | Specifies a clip region for a painter |
| QSet | Template class that provides a hash-table-based set |
| QSqlField | Manipulates the fields in SQL database tables and views |
| QSqlQuery | Means of executing and manipulating SQL statements |
| QSqlRecord | Encapsulates a database record |
| QStack | Template class that provides a stack |
| QString | Unicode character string |
| QStringList | List of strings |
| QTextBoundaryFinder | Way of finding Unicode text boundaries in a string |
| QTextCursor | Offers an API to access and modify QTextDocuments |
| QTextDocumentFragment | Represents a piece of formatted text from a QTextDocument |
| QTextFormat | Formatting information for a QTextDocument |
| QUrl | Convenient interface for working with URLs |
| QVariant | Acts like a union for the most common Qt data types |
| QVector | Template class that provides a dynamic array |
| QX11Info | Information about the X display configuration |