The new deal will keep him at the club until the summer of 2020.
The Congolese international has made 21 appearances this season, scoring once, after signing as a free agent in September.
Dikamona has become a popular figure among the Hearts support with his all-action defensive displays and his personality on social media.
The 28-year-old formed a fine defensive partnership with Jimmy Dunne when John Souttar and Christophe Berra were out injured earlier in the campaign.
He also put in a memorable performance in the 1-0 win at Easter Road at the end of December.
“I’m very happy because I have another year to show that I can bring something to this team,” Dikamona told the Hearts website.
“Of course, I have enjoyed my time at Hearts so far. Every year, since I started playing football, I have aimed to play at a higher level and now I am at a big club in Hearts.
“We are playing for the top spots in the league, Europe and a cup final and I hope that next season we can play for even more. It’s the first time I’ve had the opportunity to play in two semi finals in one season so I am really enjoying it here.
“I think that if I am popular with the fans then it is because I try to give everything on the pitch. The fans recognise that I give everything that I have and I am very happy for that. I want to say thank you to them, and I will just keep going and give everything that I have.”
Levein also confirmed that the club are interested in signing Livingston centre-back Craig Halkett on a pre-contract agreement.
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