Wilhelmina Slater is a person.
Wilhelmina Vivian Slater ( born Wanda Slater ) is a fictional character in the American dramedy series Ugly Betty . She is played by Vanessa Williams , who received a supporting actress award at the 2007 and 2008 NAACP Image Awards , a Best TV Villain award at the 2007 Teen Choice Awards and a supporting actress nomination at the 59th , 60th , and 61st Primetime Emmy Awards for her portrayal of the character . Her name is similar to Wilhelmina Cooper , a successful model who eventually established her own modeling company in the 1960s . In June 2010 , Entertainment Weekly named her one of the 100 Greatest Characters of the Last 20 Years . In July 2012 , She was on the # 25 list of TV 's Greatest Villains of All Time .