The toll in 2016 was 227 after 214 in 2015, the Office for the Coordination of Humanitarian Affairs (OCHA) said in a report.
Boko Haram launched an insurgency in northeast Nigeria in 2009 that in 2015 spilled into Niger. It also affects the country's other neighbours, Chad and Cameroon.
Overall, more than 20 000 people have been killed and more than 2.6 million displaced in the conflict.
In Niger, the Diffa administrative region in the southeast of the country, which lies on the frontier with Nigeria and Chad, bore the brunt of the attacks.
The worst-hit district in terms of the number of assaults was Gueskerou, while the highest number of victims was recorded in Kabalewa.
The OCHA report did not detail the number of military casualties.