Is there a way to remove the separator line from a UITableView?

You can do this with the UITableView property separatorStyle. Make sure the property is set to UITableViewCellSeparatorStyleNone and you're set.

Objective-C

self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;

In Swift (prior to 3)

tableView.separatorStyle = .None

In Swift 3/4/5

tableView.separatorStyle = .none

You can do this in the storyboard / xib editor as well. Just set Seperator to none.

I still had a dark grey line after attempting the other answers. I had to add the following two lines to make everything "invisible" in terms of row lines between cells.

self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
self.tableView.separatorColor = [UIColor clearColor];

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
}