The patient, a Somali man in his 30s, is being treated with an antibiotic cocktail to control the resistant TB, The Guardian reported.
A spokeswoman at Gartnavel General Hospital in Glascow, Scotland, said health officers were tracing people who may have come into close contact with the man.
Because the airborne disease is easily spread, the World Health Organization has warned of the danger XDR-TB can pose worldwide.
XDR-TB shows resistance to both first- and second-line drugs used to treat strains TB. Treatment can take between a year and 18 months and cost more than $200,000 per patient, The Guardian said.
"XDR-TB is no more infectious than ordinary TB but does require different treatment," Dr. Oliver Blatchford, a consultant with the Greater Glasgow and Clyde public health unit, told the newspaper. "The contacts of this case are being screened in the same way as ordinary TB contacts and will be monitored closely to ensure that any further cases are identified early and treated quickly."