Is it illegal to drive barefoot?

My best friend's ex did that one time in summer and was stopped by the police for a routine check but he did not get into trouble. However because of sweating, his feet was smelly, lol

As long as your choice of footwear does not impair your ability to drive and you remain in control of the car, you're fine.

However if you're involved in an accident and upon investigation, they find out you couldn't control the car properly because you were not wearing any shoes and that made your foot slip, then there's grounds to prosecute you.

Some people cannot feel the pedals properly when they don't have the correct footwear on, therefore make sure you're able to drive at ease and with full confidence barefoot if you're planning to do this.

There's no law which says you can't drive barefoot. Actually you can wear whatever you like, slippers, boots, flip flops or anything else as long as it doesn't impair your driving.