Pac Man touched down in Brisbane late on Saturday with a large entourage for his WBO welterweight title bout at Suncorp Stadium in Brisbane next weekend.
"In all my years of boxing, I have never been as motivated and fired up as this fight," Pacquiao told reporters at the airport.
"My team is very happy with my preparation. I am looking forward to this and I will be going home as world champion."
Pacquiao (59-6-2, 38 knockouts) is a clear favourite against Horn, although the Filipino great has not stopped an opponent since his 12th round TKO of Miguel Cotto in 2009.
The eight-weight world champion has said he is using the bout as an opportunity to prove he remains a global force at the age of 38 as he juggles boxing with a full-time job as a senator in the Philippines.
"I'm so thankful for this great opportunity to be here in Australia and fight here, and the warm welcome of the people here," Pacquiao said.
"I think this is one of the biggest crowds that I'm going to fight to. I love the fans shouting and cheering for me, or for Horn. I like that, it's exciting."
Pacquiao, who briefly retired early last year before making a successful comeback against Jessie Vargas in Las Vegas in November, will need to be on song against the unbeaten Horn, who has won 16 of his 17 fights with one draw.
A relatively unknown physical education teacher, the 29-year-old Australian has been dubbed the "fighting schoolteacher" by promoters, who say the 50,000-seat Suncorp Stadium is almost sold out.
"I consider him a tough opponent," Pacquiao said. "I never underestimate my opponent. He's undefeated, he's young. I like aggressive fighters."
