The popular aristocrat was the guest of honour at the premiere of the actor's new film, Mission Impossible 4.
Tom looked thrilled to see the 85-year-old, greeting her with an affectionate hug on the red carpet.
The newlywed duchess – Cayetana Fitz-James Stuart – had donned one of her colourful and distinctive 'hippy' frocks for the occasion, with a wide collared fur coat to protect against the cold.
Cayetana, the Duchess of Alba, took Tom's arm to pose for photographers, with her 61-year-old husband Alfonso Diez by her side.
She has made a full recovery since breaking her hip during a fall at home in October.
The aristocrat – who the world saw dancing with joy on her wedding day – got to know Tom when he was filming Knight and Day in Seville a few years ago.
She attended the 2010 premiere, posing between Tom and his co-star Cameron Diaz at the city's Lope de Vega Theatre.