We played them at Old Trafford in 1998 before we met Arsenal in the FA Cup final.
Sadly, our cup dream is over.
Liverpool won 3-1 at Bournemouth on Wednesday night, while Chelsea put out a strong side to win by the same margin at Derby on Tuesday.
Chelsea boss Jose Mourinho won his first trophy in England by beating Liverpool to the League Cup in 2005, and his side will be away in the first leg.
"It will be a fantastic tie," Liverpool manager Brendan Rodgers told Sky Sports.
"If you want to win this competition you have to play against the good sides.
"The most important thing was getting through, but our performance was brilliant.
"We're into the semi-final, it's over two legs and it didn't matter who we got. We needed to get there, it's Chelsea and we look forward to it."
The ties are set to be played on January 20 and 21 and January 27 and 28.