The suspect was arrested on Monday night along with a suspected local kidnapping ring, Colonel Lloyd Miles of the 25th Infantry Division said at the US military base at Kirkuk's airport.
Miles provided no further details about the detainee, but said troops arrested eight Iraqis suspected of involvement in a recent wave of tit-for-tat kidnappings between Kurds and Arabs.
The ethnic tinderbox of Kirkuk is the scene of frequent violence between Arabs, Kurds and Turkmen.
The Jordanian-born al-Zarqawi has a $25 million bounty on his head and is blamed by both the Iraqi interim government and the United States for some of the bloodiest attacks in Iraq during the 15-month-old occupation.
The US also alleges al-Zarqawi has links with al-Qaida, although some analysts say the Jordanian's threat is exaggerated and he may not even be alive.