Is it ok to lift weight after a hernia operation?

Depends.: The best answer to your question would be from the surgeon who performed the operation. How long after? How big of a hernia? Was mesh used? Where was the hernia/what type of hernia? What type of repair was done? These all need to be taken into consideration.

Not immediately: No, but after proper healing, yes. A lot depends on location, size, and severity of hernia. Ask your surgeon for specific advice.