How to remove the blank space at the top of a grouped UITableView?

The space is there because of the UITableView‘s tableHeaderView property. When the the tableHeaderView property is nil Apple defaults a view. So the way around this is to create an empty view with a height greater than 0. Setting this overrides the default view thereby removing the unwanted space.

This can be done in a Storyboard by dragging a view to the top of a tableView and then setting the height of the view to a value of 1 or greater.

Or it can be done programmatically with the following code:

Objective-C:

CGRect frame = CGRectZero;
frame.size.height = CGFLOAT_MIN;
[self.tableView setTableHeaderView:[[UIView alloc] initWithFrame:frame]];

Swift:

var frame = CGRect.zero
frame.size.height = .leastNormalMagnitude
tableView.tableHeaderView = UIView(frame: frame)

Comments

As others have noted you can use this same solution for footers.

Sources and Acknowledgements

See the Documentation for more details on the tableHeaderView property.

Thanks to @liushuaikobe for verifying using the least positive normal number works.