No, they are two spellings of the same region.
Macao = Macau
Both spellings are are acceptable. Macau is more common.
Bem vindo a Macau (for a man)Bem vinda a Macau (for a woman)"Welcome to Macao" would be "Bem vindos a Macao"
The Venetian Macao was created in 2007.
Macau is located on China's southern coast
That is one correct spelling of the proper noun, Macao or Macau, a city and special division of China.
Macau and Hong Kong
The floor area of The Venetian Macao in Macau is 980,000 m2 (10,500,000 sq ft).
Macao Science Center was created in 2009.
In Macao, it is forbidden for government employees to gamble at the casinos.
Portugal administers the government of the territory of Macao.
noAdded: Macau (Macao) is considered a "specal administrative district" of the People's Republic of China which has no extradition treaty with the US.