Wentz and Simpson wed in LA

Singer Ashlee Simpson and her Fall Out Boy fiance Pete Wentz have tied the knot in a simple ceremony in California, according to US reports.

A spokesperson confirmed to the American magazine People that the couple had indeed got married, with the ceremony held in the Simpson family's back garden and the service performed by Simpson's father Joe.

"We're delighted to confirm that Pete Wentz and Ashlee Simpson were married in front of family and close friends," said the source.

Some 150 guests are reported to have watched the pair exchange vows, including Nicole Ritchie and Good Charlotte vocalist Joel Madden, as well as Scrubs actor Donald Faison.

Jessica Simpson and her boyfriend Tony Romo were also in attendance, with the former taking the role of maid of honour for her sister, despite rumours of jealousy between the two.

Meanwhile, Wentz's pet bulldog Hemingway acted as the ring-bearer in what has been described as an Alice in Wonderland-themed ceremony.

Simpson, 23, wore an ivory gown designed by Monique Lhuillier and jewellery by William Noble.

However, speculation that Simpson is pregnant continues to circulate, with People appearing to confirm the rumours in the post-wedding report.

Wentz, 28, has so far strenuously denied such claims, having emailed MTV last month to call the suggestions a "witch-hunt".