The actress - who provides the voice of Meg in MacFarlane's hit animated show Family Guy - said that the actor and comedian did "a fantastic job", according to Entertainmentwise.
Speaking at a press conference for her forthcoming film Oz the Great and Powerful, Kunis admitted that she had only seen clips of the awards show, but was impressed by MacFarlane's performance.
"I was flying so I missed all of it, literally. I was told though that he did an amazing job, and I'm sure that he did a fantastic job," she said, describing him as "brilliant" and "so talented".
"I believe that Seth was born to host the Oscars. There's nothing that that man cannot do, so [in] the little bit of clips that I have seen, he was great and I think he's done a fantastic job."
MacFarlane has been criticised by some for a musical skit that he performed during the opening segment of the televised ceremony.
The song - titled 'We Saw Your Boobs' - referenced films in which the audience saw various actresses' breasts on screen, including during scenes depicting rape. It was deemed sexist by several commentators and viewers, and sparked a number of reactionary parodies.
Oz the Great and Powerful, which also stars James Franco and Rachel Weisz, is released in cinemas in both the US and UK on March 8.
Watch a trailer for the Sam Raimi film below: