My fiance entered the U.S illegally just over a year ago can he become legal without leaving the U.S? We just had a baby together, I need him here.

Presuming that you are a U.S. citizen or a lawful permanent resident, you can petition the government for a permanent resident visa (green card) for your fiance after you get married.  Unless he entered legally, which you state he did not, or he is eligible for adjustment of status under section 245(i) of the Immigration and Nationality Act, he will need to obtain his green card at a U.S. consulate outside the U.S. To be eligible under section 245(i), a green card petition must have been filed for him, or his parents if he was under 21 at the time, prior to April 30, 2001. Since he has been in the U.S. illegally for more than one year, he will be subject to a 10-year ban on returning to the U.S. legally.  As the spouse of a U.S. citizen, he will be eligible to apply for a waiver of the 10-year ban if he can show sufficient hardship to you if he is not allowed to return for ten years.   If your fiance has ever been caught at the border or been deported from the U.S., he will have other obstacles to getting his green card.  I strongly suggest that you contact an experience immigration attorney in your area before you file any applications with the government.   Good luck! Mark