Australian prime minister Julia Gillard praised Baroness Thatcher for her "strength of conviction".
She said: "Her service as the first female prime minister of the United Kingdom was a history-making achievement.
"Her strength of conviction was recognised by her closest supporters and her strongest opponents.
"I extend my sincere condolences and those of my fellow Australians to her family and friends."
More top news
ITV News correspondent Duncan Golestani pays tribute to a fearless young Kurdish journalist he trained in Iraq.
ATM machines were affected, while people also reported problems using cards in shops.
Representative Darrell Issa, who is from California, has said there should be a special prosecutor investigating Russian hacking and Trump.