Wozniacki was seeded second in Girls' Singles in the year's last major tournament. In the first round she won the first set against Russian Alexandra Panova, but was disqualified in the second set for verbally abusing an umpire. Wozniacki was said to have used an expletive in referring to a linesman who made a disputed call; however, on her blog, she claimed to say "take your sunglasses of [sic]" and was mistaken for talking to the linesman, when she in fact was criticizing herself after the next point.
Caroline Wozniackin her last junior tournament, the Osaka Mayor's Cup, she won both the girls' singles and doubles.
Her first title on the senior tour came shortly after on 29 October, when she won the $25,000 ITF-tournament in Istanbul by beating Tatjana Malek in the final.
Wozniacki was set to face Venus Williams on 27 November in an exhibition match in Copenhagen, but five days before the event, Williams canceled because of an injury. The two did, however, face each other in the Memphis WTA Tier III event on 20 February. Williams beat Wozniacki, ending the nine-match winning streak Wozniacki had at the time.
On 30 November, Wozniacki was named ambassador for Danish Junior Tennis by the Culture Minister of Denmark at the time, Brian Mikkelsen.
In January, she was invited by Hong Kong Tennis Patrons' Association to play in the exhibition tournament Watsons Water Champions Challenge.
Caroline WozniackiOn 4 February, she won an $75,000 ITF singles title in Ortisei, Italy, beating the Italian player Alberta Brianti 4–6, 7–5, 6–3. On 4 March, she won the $75,000 ITF tournament in Las Vegas, beating top-seed Akiko Morigami in the final 6–3, 6–2.
She obtained a wild card for the Pacific Life Open main draw and made her Tier I debut there. She was knocked out in the second round by Martina Hingis 6–1, 6–3. The two faced each other again on 27 April in Copenhagen for an exhibition match, where Wozniacki again lost 7–6(7), 3–6, 6–2.
She then made the semifinals of the AIG Open in Tokyo in October, her first career WTA Tour semifinal, and as a result became the first Danish woman to reach a WTA semifinal since Tine Scheuer-Larsen at Bregenz in 1986. Wozniacki eventually lost to Venus Williams 6–3, 7–5.