A former member of the Republican Party, Djou briefly served as U.S. representative from Hawaii's 1st congressional district from May 2010 to January 2011.

graduate degree in strategic studies at the US Army War College where he was a resident student and Carlisle Scholar.

In 2006 he was selected as one of the 40 most promising leaders in Hawaii under age 40 by Pacific Business News, and in 2005 was named by Honolulu Weekly as the "Best Politician" in the state.

Catalani faced controversy in the campaign, with allegations that she broke a promise to the Outdoor Circle, a community beautification organization,[11] by posting yard signs.

He opposed the state "van cam" program launched in 2002 to catch speeders using automated cameras instead of police officers, and successfully campaigned for its elimination.

[18] In 2002, Djou was elected to the Honolulu City Council, representing District IV (Waikiki to Hawaii Kai).

In March 2008, Djou announced well ahead of time that he would run for U.S. Congress in the 2010 cycle, seeking Hawaii's 1st congressional district seat.

[25][26] Among the candidates Djou defeated were former Congressman Ed Case and State Senator Colleen Hanabusa, two Democrats who together polled over 58% of the vote.

[28] He followed Abercrombie and Patsy Mink as the third person to have been in the Honolulu City Council, Hawaii State Legislature and U.S. Congress, and was the first to be elected to all three chambers before age 40.

[31] On May 28, 2010, Djou spoke on the floor of the House in support of approving the South Korean Free Trade Agreement, which was signed by former president George W. Bush on June 30, 2007.

A major in the U.S. Army Reserve, Djou suspended his campaign for six months while deployed to Afghanistan with the 3rd Brigade Combat Team, 10th Mountain Division, from September 2011[39] to March 2012.

In the nonpartisan race, Djou had already received the endorsement of former governor Ben Cayetano, an anti-rail Democrat.

[48] Though both candidates supported the municipal rail project, its cost overruns were an issue, as well as Caldwell's alleged interference with the Ethics Commission.

[50] In 2018, Djou left the Republican Party, citing concerns with its policies and President Trump's character.

[55] Djou wrote, "while it is clear to all that Honolulu is in desperate need of dramatic change and real leadership, I have come to the difficult decision that I am not the best person to lead this charge in the 2020 election."

In addition to his decision not to run for mayor of Honolulu, Djou announced he was selected to serve in the United States Army War College to complete a graduate degree in Strategic Studies.

With his decision to set politics aside, Djou wrote, "completing War College will better position me to assume more significant future roles and duties in service to our country.

[4] In August 2024, Djou wrote an op-ed for Fox News praising 2024 Democratic vice-presidential nominee Tim Walz.

[59] This originates from his grandfather's work at a French engineering company in Shanghai in the 1920s, where he was referred to as "Dijou", a name he later wrote on his immigration papers.

[59] Since 2010, Djou has contributed op-ed articles as a writer for Honolulu Civil Beat, a local nonprofit journalism website.