According to the survey, 83% of over-60s said they had been victims of age discrimination, and 73% of 51-60-year-olds said age was the main reason they had been rejected for a job.
The survey, of more than 1,400 UK people over 50, found 57% of over-60s have been unemployed for more than six months. That is nearly twice the number of 25-34-year-olds out of work (30%) for this length of time.
Nearly half (46%) of senior jobseekers (those aged over 51) have applied for more than 50 jobs in the last six months, with two-thirds only receiving five or fewer responses from employers. That is despite around 90% of the older jobseekers having the relevant skills to do the job.
The research also found around 80% of senior jobseekers don't put their date of birth on their CV.
Totaljobs director John Salt said it was "alarming" to see so many senior jobseekers "disadvantaged" because of their age.
"Many employers don't realise that age discrimination is illegal, just as it is for gender, religion, sexual orientation, disability or race," said Salt.
"Older jobseeker can bring years of experience to the workplace, benefiting UK employers. Many employers have witnessed firsthand just how beneficial it can be to have employees from all different levels of experience."
