A report claimed earlier this week that the 'X Factor' mogul was intending to marry Silverman close to his elderly mother Julie's home in Sussex early next year.
However, a spokesperson has now dismissed the story as not true, reported Hello! magazine.
"Simon and Lauren are very happy but this story is not true," he said.
Silverman is due to give birth to the couple's child early next year.
The star, who is currently starring in the US version of the 'X Factor', revealed they were expecting a baby boy in September.