Two officials who spoke to the news network said Rodman, 56, is visiting the country ruled by dictator Kim Jong Un.
Rodman described Kim as his "best friend" in January 2014, the last time he visited the country.
Tensions have increased dramatically between the United States and North Korea since that time. North Korea has already launched several missiles in 2017 – most recently firing four anti-ship cruise missiles that each flew about 124 miles.
A senior Trump administration official told Fox News that Rodman is "going as a private citizen."
"It's our understanding he hasn't landed yet," the official said, according to the report.
Rodman is the first high-profile U.S. citizen to pay a visit to the country since U.S. President Donald Trump assumed office in January.
The former basketball player has ties to the president, and was a former contestant on the Celebrity Apprentice, Trump's reality television show.
Rodman also showed support for Trump in the course of his presidential campaign in 2016.
CNN reported the Hall-of-Famer was seen at Beijing International Airport but refused to answer any questions.
In 2014, Rodman called attention to the imprisonment of Kenneth Bae, a U.S. citizen and missionary who had been in North Korea detention for two years.
Bae has said Rodman's plea to Kim to "do me a solid" and other public remarks was the catalyst for his release.
North Korea continues to detain four U.S. citizens: Kim Dong Chul, a Virginia businessman, Otto Warmbier, a University of Virginia student, Kim Sang Duk, a university professor, and Kim Hak-dong, also a university professor.