On January 30, 2009, Villarreal agreed to loan Altidore to Xerez, leader of the Segunda División at the time of the transfer, until the end of the 2008–09 season. It was expected that the move would allow Altidore to get more playing time, and also allow him to continue the process of assimilating into the Spanish culture.
On April 16, 2009, Altidore underwent minor surgery on an injured toenail that required more than a month of recovery, resulting in him never making an appearance for Xerez.
On August 5, 2009, Altidore announced on his Twitter page that he would be loaned to English Premier League club Hull City. He joined Hull City the next day on a season-long loan with the option for Hull City to purchase his rights at the end of the 2009–10 season for a fee believed to be £6.5 million ($11 million).
On August 10, 2009, Hull City announced that they were successful in obtaining a work permit for Altidore. Altidore made his debut for Hull on August 22, 2009, coming on as a second-half substitute against Bolton. He provided the assist for Kamel Ghilas to score the only goal in a 1–0 home victory at the KC Stadium. On August 25, 2009, Altidore scored his first goal for Hull in a 3–1 win over Southend United in the second round of the League Cup. Altidore was popular with supporters but struggled to make a lasting impact with the Tigers as his finishing was often found wanting, however he did manage to score his first and only Premier League goal in the 2–1 home win over Manchester City on February 6. On April 24, in an important game for Hull City's Premier League survival, he was dismissed for violent conduct after a spat with Sunderland's Alan Hutton who was also sent off. Hull City lost 1–0 and were all but relegated from the top flight.
On March 28, 2009, Altidore scored his first away goal in World Cup Qualifying in the 2–2 draw with El Salvador. On April 1, 2009, Altidore scored three goals in a 3–0 victory over Trinidad and Tobago, making Altidore the youngest American to score a hat-trick in an international game.
On June 24, 2009, Altidore scored in the semi-final of the 2009 FIFA Confederations Cup against Spain, turning club teammate Joan Capdevilla to get a clear shot on Iker Casillas' goal. The U.S. went on to defeat the Spanish team, 2–0.