My two-year-old hasn't started walking yet, though he can stand up on his own and walk with support. My wife and I are worried about it. Should we go to a doctor or wait for some more time?

You should always consult a doctor in such cases. But every kid learns and grows differently. There is no such time period or age of learning things for kids. It has been observed that toddlers do not try walk if they get support in moving around like holding objects or walkers. You would never learn to swim until you get into deep waters - same concept applies to your baby.