The 'American Idol' judge showed the ultimate declaration of his love for the actress on US TV's 'The Jimmy Kimmel Show' where he unveiled his new inking during a performance to promote his latest album 'Fuse', reported Ace Showbiz.
Urban made sure no-one missed the romantic gesture by wearing a short sleeved top while he crooned away on his guitar.
The 45-year-old star already had the name of the actress etched onto his right arm in script font, but now sports a re-worked version of the tattoo featuring an additional Celtic design around the original inking.
Kidman also has two adopted children, 18-year-old, Connor and 20-year-old Isobella, with her ex-husband Tom Cruise.