The 'Edge of Tomorrow' star is said to have been smitten with the Australian model after meeting her at a social event just a month after she announced her split from her husband Orlando Bloom - with whom she has three-year-old son Flynn.
An insider told Australia's New Idea magazine: "Since last November, when they were introduced at a private dinner in London, Tom hasn't been able to get Miranda out of his mind!"
The 52-year-old actor has been single since his marriage to former 'Dawson's Creek' star Katie Holmes broke down in 2012 but is now said to be dating Miranda, who was previously rumored to have been dating her close friend James Packer.
The source continued: "With James out of the way, Tom and Miranda have exchanged several phone calls and have even met up in secret every time she's flown into London. He's smitten!"
Miranda is also said to remind Tom - who has daughter Suri with Katie - of his ex-wife Nicole Kidman, with whom he has son Connor and daughter Isabella.
The sourced added: "She's even more gorgeous than Katie and has that sexy Aussie accent that made him fall in love with Nicole [Kidman]."
Meanwhile, Miranda is said to be just as taken with Tom - who also has a failed marriage to actress Mimi Rodgers under his belt.
A friend of the supermodel said: "Miranda loves rich men, powerful men and Tom ticks all those boxes."