One journalist is being killed every five days as a result of their work, UNESCO reported on November 2.
Of the 827 journalists killed in the last 10 years, 115 were killed last year, making 2015 the second-deadliest year of the decade for journalists, the report said.
Syria and Iraq, where the Islamic State executed several journalists in highly publicized beheadings after establishing its so-called caliphate there in 2014, were by far the most dangerous places for journalists to work, accounting for 24 deaths in 2014 and 23 in 2015.
But Ukraine and Afghanistan were also killing fields for journalists in 2014, with seven losing their lives in Ukraine and five in Afghanistan. In Pakistan, four journalists were killed in both 2014 and 2015.
UNESCO, the United Nations' cultural arm, said less than one in 10 of all deaths have been solved, while "numerous other violations endured by journalists, which included kidnappings, arbitrary detention, torture, intimidation, and harassment" were not chronicled in the report.
Most of the victims were local journalists, including freelancers who work independently and often without adequate protections, UNESCO said, calling such contract workers "the most vulnerable group in the media sector."
With reporting by dpa