The pair inherited the title from last year's winners Carol Vorderman and Anton du Beke after topping a public vote.
Speaking after her victory, Gulati - who plays Sunita Alahan on the ITV soap - declared: "I am really honoured and flattered to be a winner of this year's competition and for my bum to be etched into the history of the award's alumni - a list which includes so many other distinguished bottoms.
"And I'd also like to say... in the words of will.i.am, 'I got it from my mama'."
Barrowman added: "With tush tightly toned, cheeks firmly clenched and a big smile on my face, I'm thrilled to be awarded the accolade."
The Torchwood star also posted a thank you message on Twitter in which he revealed that he won 'Rear of the Year' "by a landslide".
Gulati and Barrowman were described by Sally Allen of sponsors Wizard Jeans as "two excellent examples of this year's ideal rear".
She said: "Shobna's slim but womanly silhouette is a fine example of the happy, healthy female form for 2012 and John's rear is clearly admired on an international basis, judging by the number of fans who voted for him. No doubt his dancing prowess helps to keep him in tremendous shape."
Previous winners of 'Rear of the Year' include Jennifer Ellison, Rachel Stevens, Will Young and Gulati's Corrie co-star Ryan Thomas.