In a national Galaxy poll published in yesterday's News Ltd newspapers, Labor on a two-party basis would receive 49 per cent of votes compared to the Coalition's 51 per cent.
Rudd also led in the preferred prime minister stakes, scoring 51 per cent compared to Tony Abbott's 34 per cent.
During his first appearance among the public as leader, Rudd was greeted by throngs of well-wishers as he walked through the small town of Springwood, in a marginal seat on the outskirts of Sydney on Saturday.
Mothers thrust their babies into his arms, drivers honked their horns and teenagers posed with him for photographs.
The town "flocked to see Rudd as if he were a Messiah", local media reported.
At a Presbyterian church barbecue, Rudd stopped to buy a sausage sandwich and declared: "It's good to be back".
During much of his first term as Prime Minister, Rudd was one of Australia's most popular leaders. But he was despised by many of his Labor colleagues.
A ReachTel poll last week showed Labor has received an immediate 10 per cent boost in four key seats.
Asked about his party's poll boost, Rudd said: "Let's not get too ahead of ourselves. I think we're doing okay, but we've got a long, long way to go."
Gillard's departure has left questions in Australia about the extent to which her downfall was the result of a series of personal and sexist attacks.
An Opposition MP, Michaelia Cash, said the country's most senior female minister, Penny Wong, who was promoted after backing Rudd, had been "drinking from the chalice of blood".
She added: "I wonder how loud former Prime Minister Gillard screamed when the sisterhood knifed her in the back and took her out." Wong, the finance minister and now the Leader of the Senate, said Abbott had encouraged the sexist attacks against Gillard and given a "green light to the baying wolves".