Form 0 0 809 238 Form 10 Button 1 Button 2 <html><head/><body>The buttons below have 0 spacing between the in Fusion style. The solution I found was to override layoutSpacing in my custom style. //The documentation says this is only used if PM_LayoutHorizontal/VerticalSpacing returns a negative value //That is not true. In cases where a QBoxLayout is embedded in a QGridLayout which has one spacing overridden, it will fall back to this function via QBoxLayoutPrivate::setupGeom() int MyStyle::layoutSpacing(QSizePolicy::ControlType control1, QSizePolicy::ControlType control2, Qt::Orientation orientation, const QStyleOption* option, const QWidget* widget) const { Q_UNUSED(control1); Q_UNUSED(control2); return pixelMetric(orientation == Qt::Horizontal ? QStyle::PM_LayoutHorizontalSpacing : QStyle::PM_LayoutVerticalSpacing, option, widget); }</body></html> true Qt::Vertical 20 40