Castroviejo, who turned pro in 2010, has carved out a reputation as a world class time triallist.
Hailing from Getxo in Spain, the 30-year-old has spent the last six seasons with Movistar. He has completed all three Grand Tours, helping Nairo Quintana to victory in both the 2014 Giro d’Italia, and last season at the Vuelta a Espana.
He is the current and three-time Spanish national time trial champion and won the European Championship title in 2016. He has also claimed stage wins at the Tour of Romandie and Volta ao Algarve.
A powerful rouleur and a strong climber, his all-round capabilities will make him a key addition to the team’s stage race roster.
Castroviejo says he is “very excited” to be joining Team Sky.
“Everybody knows the strength in the team, and how important the spirit between the riders is to the team’s success. I’m really looking forward to being part of that, bringing my own experience and learning new things.
“I have been part of Grand Tour winning teams in the past and I want to do that again in the future. I’m happy to be taking this next step with Team Sky.