About 700 activists attending the RedState Gathering in Charleston gave Perry a standing ovation as he appeared at 1 p.m., the campaign said.
"It's time to get America working again. It's time to give a pink slip to the current residents of the White House," he said.
Perry also touched on conservative social themes, mentioning his small-town roots in Paint Creek, Texas, his long marriage and his opposition to abortion. He called for greater support for Israel, saying President Obama has "insulted our friends."
Shortly before his speech, Perry also made his candidacy official in a conference call with South Carolina Republicans, The Wall Street Journal reported.
Perry's announcement appeared calculated to distract attention from the Iowa Straw Poll, which was under way in Ames Saturday.
Before his announcement, South Carolina Gov. Nikki Haley told activists at the Francis Marion Hotel they have a "superstar" appearing before them, USA Today reported. She later backtracked a bit, telling reporters the Republican field is full of superstars.
Perry has done well in polls of Republican voters. He appears to appeal to many voters because he combines more than 10 years as Texas governor with the values of the party's Christian evangelical wing.
But Perry also comes from the same state as President George W. Bush, which could turn off many voters, including some Republicans.