West Yorkshire Police recorded 243 incidents of sexual communication with a child between April 2017 and September 2018, according to Freedom of Information requests from the NSPCC.
Social media sites and apps such as Facebook, Snapchat and Instagram were used in nearly two-thirds of cases where police recorded the method of contact, with 113 victims over the 18-month period.
Girls aged between 12 and 15 were the most likely targets, but one in four victims were 11 or younger, according to the reports which also include an age.
The NSPCC has called for tougher measures to tackle grooming, after its investigation found more than 5,000 reports of sexual communication with children across a total of 39 police forces.
NSPCC chief executive Peter Wanless accused social media firms of “10 years of failed self-regulation”.
He said: “These figures are overwhelming evidence that keeping children safe cannot be left to social networks.
“We cannot wait for the next tragedy before tech companies are made to act.”
A spokesperson for Facebook and Instagram said: “Keeping young people safe on our platforms is our top priority, and child exploitation of any kind is not allowed.
“We use advanced technology and work closely with the police and Child Exploitation Online Protection Command to aggressively fight this type of content and protect young people.”
Chief Inspector Wayne Horner from West Yorkshire Police’s Safeguarding Central Governance Unit said: "West Yorkshire Police take all reports of child sexual exploitation and online grooming very seriously and are treated in the strictest confidence.
"We work closely with partners in schools to make young people aware of the dangers of using the internet.
‘"The force runs two campaigns ‘Know the signs’ and ‘Who R U Talking 2’ with partner agencies to raise awareness of the issues and how parents can identify the signs that a child is potentially at risk.
"Child Sexual Exploitation is a top priority for West Yorkshire Police and we are committed to tackling it by working in partnership with other agencies.
"For more information about online grooming and advice for parents and children, please see the cyber crime section on the Help/Advice page at www.westyorkshire.police.uk "