The latest figures from the ICO show the voluntary sector reported 29 incidents between April and June 2016, compared with 11 in the same period a year before.
The number of incidents in the voluntary sector has been rising steadily over the past year, with 23 reported in both January to March 2016 and October to December 2015, and 17 between July and September 2015.
An ICO spokeswoman said the recent investigations into and publicity about data protection practices in the charity sector "will have had an impact".
She said: "We’ve been open about our investigations into charities and it’s reasonable to conclude that more charities are reporting possible breaches to us because they know the sector is under scrutiny."
The ICO said cyber incidents, such as hacking or phishing scams, accounted for nine of the incidents in the charity sectors most recent quarter, with the loss or theft of paperwork accounting for seven of the incidents.
Other causes included the failure to use the bcc field when sending an email or failing to correctly dispose of paperwork.
The ICO figures show the charity and voluntary sector had the sixth-highest number of data security incidents between April and June, when compared with other sectors.
The health sector was the largest offender by far, according to the ICO, with 232 incidents reported in the same time period. Local government was second with 62 reported incidents.
The ICO said it received 545 reports of incidents across all sectors over the quarter, a 22 per cent increase on the previous three months.