Who has won the tourist trophy the most times?

In the Amateur Era: Men's Singles- William Renshaw 7 times. Women's Singles- Helen Wills Moody 8 times.

In the Open Era: Men's Singles- Pete Sampras 7 times. Women's Singles- Martina Navratilova 9 times.

So Martina Navratilova tops the list of most times winners.