Not necessarily! Running could actually be good for your knees.
Some research indicates recreational runners are less likely to suffer from knee osteoarthritis than non-runners. Your body adapts to the forces placed on it so running can lead to stronger muscles in your legs and back and maintenance of good bone density.
If you overload your body by training too hard or too frequently you could cause an injury. The same study indicated that competitive runners were more likely to suffer knee osteoarthritis than recreational runners. If you are running for fun or for fitness you should still take care to avoid injury. Your trainers should feel comfortable, you should warm up with brisk walking or light jogging, increase your distance gradually and include rest days in your training plan. Personally I tend to avoid running on consecutive days.
If running causes knee pain or if you have previously suffered knee injuries you should seek professional advice. You may need to start with a lower impact exercise to build up your strength and pain tolerance. Walking, swimming or cycling are often good places to start. Specific exercises to strengthen the muscles around your knee may also be helpful.
Reference: The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis, Journal of Orthopaedic & Sports Physical Therapy
Published Online: May 31, 2017 Volume 47 Issue 6 Pages 373-390