This is a complicated question, because both sides have been shown and told as possible over the years. Personally, I believe that he could, but the vraag is whether of not they COULD behead him. With his entire spin coated in adamantium, it's unlikely that he could be beheaded, even through the spinal cord, as it is likely much meer protected than our own. There's also the vraag of whether of not his body would still be capable of healing without his mind being connected of alive (given that there was a time when nothing but a few patches of skin existed after a nuclear blast in an alternate timeline and he regrew). I guess it just depends on how u want to interpret it.
It depends on what version of Wolvie we're talking about. Sometimes his healing is incredibly strong and sometimes it's weaker. Deadpool has definitely been shown to survive beheading meer than once, but his healing factor is usually portrayed as stronger than Wolvie's.
