Ambulances and emergency response vehicles were deployed more than 1,500 times to five patients in 12 months, the BBC has learned.
A total of 8,303 emergency calls were made by the five most frequent UK callers.
An NHS spokesman said the calls were often related to mental health, chronic pain and alcohol or drug dependence.
Vicki Nash from mental health charity Mind said the figures show that individuals' needs were not being met.
The figures were released after a Freedom of Information request to the UK's 14 ambulance trusts.
The highest number of calls by a single patient were made to London's ambulance service, which was contacted 3,594 times.
Other services to receive frequent calls include East Midlands Ambulance service, which was called 1,244 times by a single patient, and South West Ambulance service, which received 1,044 calls from one person.
"Frequent callers" are classed as those who call at least five times in a month, or at least 12 times in three months, and they cost the health service almost £19m a year.
Paul Jefferies, assistant director of operations at South Central Ambulance Service, said about 10% of the calls they receive are from frequent callers.
He said: "If the ambulance, or the response vehicle, is being deployed to that patient who we know is a frequent caller, it means that a resource might not be available for a potential cardiac arrest."
Ms Nash, head of policy and campaigns for Mind, said the figures showed the service being offered was not good enough.
She said: "It's not meeting the needs of that individual, which is why they are repeatedly calling."
A West Midlands Ambulance service spokesman said misuse of the 999 number had a "huge" impact.
He said: "It's not just the financial cost, it is the effective removal of ambulances for people who really need them that is the greatest concern."
The trusts work with other agencies such as social services to put in place care packages that will stop individuals calling inappropriately, he added.
A Department of Health spokesman said: "NHS 999 call handlers do a challenging job helping callers seeking assistance in an emergency, and we expect the public to support them in their vital role by only calling 999 if necessary."