Initially planned to be released in 2007,
Tha Carter III's largest delay came after the majority of the tracks were leaked and distributed on mixtapes, such as "The Drought Is Over Pt. 2" and "The Drought Is Over Pt. 4". Lil Wayne initially decided to use the leaked tracks, plus four new tracks, to make a separate album, titled Tha Carter III: The Leak. The Leak was to be released December 18, 2007, with the actual album being delayed until March 18, 2008, The release of The Leak in this format never came to fruition, but an official EP titled The Leak and containing five tracks was released digitally on December 25, 2007.

On January 23, 2008, Lil Wayne was arrested alongside two others. His tour bus was stopped by Border Patrol agents near Yuma, Arizona. A K-9 Unit recovered 105 grams of marijuana (3.7 ounces), almost 29 grams of cocaine (1.02 ounces), 41 grams of Ecstasy (1.4 ounces) and $22,000 dollars in cash. Lil Wayne was charged with four felonies: possession of narcotic drug for sale, possession of dangerous drugs, misconduct involving weapons and possession of drug paraphernalia. He was granted permission to travel outside of the state and remain out of custody on the $10,185 bond he posted. On May 6, 2008 Wayne returned to court in Arizona to plead not guilty to the charges.
Tha Carter III was released on June 10, 2008, selling more than a million copies in its first week of release, the first to do so since 50 Cent's The Massacre in 2005.The first single "Lollipop", featuring Static became the rapper's most commercially successful song at that point, topping the Billboard Hot 100, making it the first Top 10 single for Lil Wayne as a solo artist, as well as his first #1 on the chart. It also gave him his first #1 on the Hot Rap Tracks. The second single, "A Milli", peaked at #8 on the Billboard 100, becoming the second-highest peaking single as a solo artist behind "Lollipop," and #2 on the Hot Hip-Hop/R&B Tracks charts. For the chart week of June 21, 2008, Lil Wayne tied T-Pain in having the most songs on the Hot 100 in one week for a rapper, appearing on seven songs in the Hot 100 that week. His third single from Tha Carter III, "Got Money" featuring T-Pain, peaked at #13 on the Billboard 100. Along with his album singles, Lil Wayne charted on "Girls Around the World", "Out Here Grindin", "Love In This Club, Part II", and various other singles featuring Wayne as a performer.
On June 17, 2008, Lil Wayne posted a video blog on YouTube thanking fans for buying Tha Carter III. At the end of the video, he said "Gettin' back to work. Carter IV."
Tha Carter III, nine weeks after being released, had officially become certified as double platinum selling two million copies in the United States.