Biel, 30, said they won't be having a big, lavish wedding and they will probably keep the nuptials secret, reported Daily Star.
"I do know that it's not going to be a great big to-do. This will be a very private moment for us, so we're going to keep it small and intimate," she said.
The "A-Team" star also said she would like to emulate actress Emily Blunt, who married 'The Office' star John Krasinski at a small ceremony in Italy in 2010.
"The people I'd most like us to be like are Emily Blunt and John Krasinski - it seemed like one day they were engaged and the next day they were married and nobody had known anything about it. And I did at the time think, 'Aha! That's the way to do it'," she added.
Timberlake, 31, proposed to his longterm girlfriend over Christmas and reports say they will tie the knot before the end of this year.