Willian has told the Evening Standard he will be a Chelsea player next season despite interest from former manager Jose Mourinho in bringing him to Manchester United.
Brazil international Willian has been frustrated by a lack of regular first-team football since losing his starting place to Pedro Rodriguez in October, when he was granted compassionate leave after his mother's death.
Mourinho admires Willian and is reported to have kept in contact with him, and sources told ESPN FC last month that the United manager could make an offer to take the 28-year-old to Old Trafford in the summer.
But the attacker -- who signed a new four-year contract in July and has previously voiced a desire to finish his career at Stamford Bridge -- said: "I have a contract with Chelsea until 2020 and I am very happy here.
"I have a great relationship with all the people that work at Chelsea and the fans too. They have been great to me since I joined.
"Chelsea are back in the Champions League next season and I am looking forward to playing in it again. It is a big, big target for us, and we have to look to win that trophy next year."
Despite often being used as a substitute, Willian has made a significant impact for Chelsea this season, contributing eight goals and two assists in the Premier League and scoring twice in the FA Cup semifinal against Tottenham.
The Blues take on Arsenal in the final on Saturday, and Willian said: "We want to end the season with the Double. We have the Premier League but we want the FA Cup too.
"This is a big game for us. It will be difficult against Arsenal and we have to be ready. We have to be focused and play in the same way we have all season."