The 30-year-old Lopez, who has spent the last five seasons at Villarreal after joining from Real Madrid, has penned a five-year contract with the Andalusian club.
The once-capped Spain international said on his new club's website: "It's all been very quick. I'm very happy and looking forward to wearing the Sevilla shirt and trying to help them continue being a big club.
"It's a big club for lots of things, for their fans, for what you feel when you go to play there. You always feel a little bit of envy when you experience that from outside, and now I'm very excited to be able to live it from the inside."
Sevilla, the 2006 and 2007 UEFA Cup winners, finished ninth in La Liga last season while Villarreal, having finished fourth in 2011, were surprisingly relegated after losing at home to Atletico Madrid on the final day.