- Division : Light Heavyweight
- Height : 6 ft 2 in (1.88 m)
- Reach : 77 in (196 cm)
- Nationality : Polish
- Home town : Bialobrzegi (Poland)
- Residence : Chicago , IL USA
- Bronze medal- Nationwide Youth Olympics in Hall Sports- Boxing, Starachowice, Poland 2003
- Bronze medal- Polish Junior Championship, Ostroleka, Poland 2004
- Silver medal- Polish Junior Cup, Ostroleka, Poland 2004
- Trophy for the youngest boxer- Youth Polish Championship, Ostroleka, Poland 2005
- Gold medal- Polish Junior Championship, Leszno, Poland 2005
His professional career had begun in 2006 in Ostrołęka, where he won by majority of points versus Czech fighter Miroslav Kubik. After this fight he got a chance to train and fight in the U.S. From this point he resides with his family in Chicago and trains with Sam Colonna (Andrzej Golota’s trainer). In 2009 he signed a contract with Dominic Pesoli’s 8 Count Productions. At the beginning of 2010 he decides to move to Light Heavyweight division which is better for his physical conditions. Later in 2010 he won a WBC Youth Championship, and in 2011 WBO NABO Title. On September 23, 2011, he won by TKO in second round with Jose Spearman in his home town Chicago.
On June 13, 2012 at Chicago’s UIC Pavilion, Fonfara defeated former champion Glen Johnson by unanimous decision.
Fonfara fought Adonis Stevenson on May 24, 2014, in Montreal, Quebec, losing by unanimous decision in a 12-round bout.
After fight with Stevenson he signed contract with Al Haymon.
Fonfara fought Julio César Chávez, Jr. on April 18, 2015, in Carson, California for the vacant WBC International Light Heavyweight Championship. Fonfara won the fight by technical knockout after Chavez threw in the towel before the start of the 10th round.