The deputy prime minister revealed that he last spoke to the former energy secretary, who stepped down as a Lib Dem MP after pleading guilty to perverting the course of justice, during the by-election campaign for his old seat of Eastleigh in Hampshire.
Huhne was sentenced to eight months in prison, alongside ex-wife Vicky Pryce, on Monday.
Speaking to LBC 97.3 radio, Clegg said today: "I do have mixed emotions and I feel very sad for his whole family. Whatever he's done, he still remains someone I've known for many years and a friend.
"I'm not going to say that because he's done something wrong and he's serving his time that that's not the case. That is the case."
He added: "I'm not going to airbrush out that Chris is someone I've known for many years, who is a friend, who is a close colleague, and I feel incredibly sad for his whole family, because his whole family has been engulfed by this.
"I don't think Chris would expect me to visit him in prison but I will see Chris once he...," Clegg said, trailing off at the end of the sentence.
"I haven't written to him. We've been in touch. The last time we were in touch was around the time of the Eastleigh by-election, but of course I will keep in touch with Chris once he has served his sentence.
"You can be clear someone's done something wrong and has to pay the consequences, but equally acknowledge that you can still keep in touch with them as a human being, as a friend."