The European monarch, 52, opted for a V-neck gown with floaty sleeves for the occasion.
The mother-of-three was seen arriving at Zahran Palace in Amman arm-in-arm with her husband King Willem-Alexander, 56.
As the couple entered the Palace, they were greeted by Crown Prince Hussein's proud parents King Abdullah II, 61, and Queen Rania, 52.
Maxima's show-stopping dress featured billowing sheer sleeves - making it ideal for 31C temperatures today.
The stunning A-Line chiffon gown - which was cinched in at the waist with a ribbon - featured a dainty blue floral pattern.
What's more, Maxima matched her accessories to the colour of her pretty summery dress.
The royal wore long silver necklace featuring an assortment of blue jewels and matching dangly earrings.
She also carried a navy shell-shaped woven clutch bag to carry her essentials.
Tying into her glamorous ensemble, Maxima styled her blonde hair in old Hollywood-style waves.
The stylish royal famously loves a smokey eye-look for everyday royal engagements - but opted for something more dramatic for the Royal Wedding today.
To offset her nude lipstick, Maxima donned a sweep of navy eyeshadow and highlighter on the high points of her face to give her a sunkissed glow.
Meanwhile, King Willem-Alexander was just as dapper in a navy suit and a pale blue tie, which matched the exact hue of his wife's dress.
The bride Rajwa was dazzling in a white gown for the occasion, which featured a lengthy train embroidered with flowers, and a sparkling diamond tiara.
She was given away by Crown Prince Hussein's brother Prince Hashem, who walked arm-in-arm with her through the gardens of the palace.
The mother-of-three offered a curtsey to both King Abdullah and Queen Rania, before the foursome chatted for some time.
The attendance of the British royals - who were spotted at a luxury hotel in Amman last night - had been kept under wraps, and was only confirmed by Jordanian state media a few hours before the start of the palace ceremony.
But it's perhaps hardly surprising Kate and William have made the journey to the Middle East - as both no doubt share a fondness for Jordan.
The country especially holds special memories for the Princess; the Middleton family spent three years there during the early 80s, when Kate was just two years old, after her father Michael, a British Airways manager, was relocated to Amman for work.
Meanwhile Princess Beatrice arrived moments after Kate and William, hand-in-hand with her husband Edoardo Mapelli Mozzi.
The mother-of-one opted for a stunning silver sequin gown for the occasion.Read more 2023-06-01T15:12:22Z dg43tfdfdgfd