Ministry of Justice data shows that West Yorkshire Police took action against 679 people in the 12 months to September 2018, either for possession of a knife as a weapon or threatening someone with one.
Of those 123, or 18 per cent, were aged between 10 and 17.
That number has increased by 28 per cent since 2015, when 96 children were convicted or cautioned.
Patrick Green, chief executive of anti-knife charity the Ben Kinsella Trust, said the figures were “deeply depressing” and showed enforcement cannot prevent knife crime on its own.
“This indicates we cannot rely solely on enforcement if we are going to tackle the small but significant number of habitual reoffenders.
“These are people who are stuck in a spiral of violent crime.”
Mr Green said taking public health approach, which is beginning to be adopted in some parts of the country, could start to tackle the “underlying causes of knife crime”.
Of the total number of knife offenders, 150, or 22 per cent, had at least one previous caution or conviction for carrying a knife, and 22 of the criminals had three or more past offences.
Across England and Wales, the number of reoffenders increased by 35 per cent over the last three years.
Mr Green continued: “I’m confident that a public health approach work, it will stop the next youngsters getting caught in the cycle of violent crime.
“It won’t work immediately, but given time, as we’ve seen in Glasgow and US cities, if it’s properly funded it can be successful.”
Overall 5 per cent fewer people were convicted or cautioned by West Yorkshire Police for knife offences in 2017-18, compared with the previous 12 months.
The vast majority were for possession offences, while 42 were charged with making threats with a knife.
A total of 242 offenders were sent to prison, 156 were given community orders and 86 received a caution.
Across England and Wales, in the year to September, 21,381 cases were dealt with by the criminal justice system, the highest number since 2010. In one in five cases, offenders were aged under 18.
The MoJ report said offenders are now more likely to receive a custodial sentence for knife and offensive weapon offences.
Justice minister Rory Stewart said: “Knife crime has devastating consequences on families, children and communities. Offenders simply cannot go unpunished.
“These figures show we are catching and prosecuting more of those carrying knives and other weapons, and sending them to prison for longer.
“But we must do more, and through the government’s Serious Violence Strategy we are working to prevent young people from ever picking up a knife in the first place.”