The 27-year-old has signed a four-year deal with the Easter Road outfit after undergoing a medical.
Hibs have agreed a fee of £700,000 with his club Liga Deportiva Universitaria, some £300,000 more than the £400,000 they paid Celtic for Pat McGinlay in 1994.
"He is a very exciting player and this is a very bold move by this club to get Ulises here," said a delighted Hibs boss Alex McLeish.
"I'm looking forward to working with him and hopefully he can take the club another step forward.
"This is a great signing for the club and I think it's an imaginative move by the club.
"He is without doubt a very good player and we are very confident after he settles in the country that he'll bring a lot of assets to this club.
"Like I said he can take the club a step forward and I'm looking forward to working with Ulises on the training pitch and in general play."
