Common lizards have long bodies and short legs. They have coarse scales which range from grey, brown, bronze or green on the back, and males are generally darker than females. They have a series of white spots down the flanks, which fuse to form a line, and a black line along the back. Common lizards also have numerous black spots scattered over the body. Males have orange/yellow bellies with black spots and females have cream/white bellies.
Common lizards are active during the day and spend the morning and afternoon (but not the intense heat of midday) basking in the sun either alone or in groups, going to find food when their body temperature reaches 30 degrees Celsius. They are good swimmers and will dive underwater when threatened. At night, and when startled, they will shelter beneath logs, stones and metal sheets. Common lizards hibernate from October to March. They will often hibernate in groups, and sometimes emerge for a brief time during warm spells.
Common lizards hunt insects, spiders, snails and earthworms. They stun their prey by shaking it, and then swallow it whole.
After emerging from hibernation, the males defend breeding territories from other males. The young develop over 3 months within egg membranes inside the female's body, which they usually break out of as she gives birth. They may however remain inside the egg membrane for several days before breaking out (using their heads rather than an egg-tooth to rupture the membrane). Litters of 3-12 young are born from June to September, after which time the mother shows no parental care. The young feed actively from birth and quickly disperse. Males become sexually mature around 2 years and females around 3 years of age.