When SSL was introduced in ~1996, there was only a few CAs issuing certificates for that specific use and a few sites which actually used SSL.
Which Certification Authority issued the first SSL certificate and whom was it issued to?
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Spelunking through https://crt.sh, one finds a CA certificate for RSA Data Security, Inc., from 1994, but the oldest certificate it has issued has a validity period starting only on 1998-02-13. That doesn't mean that that CA didn't issue certificates before—maybe the records in crt.sh are incomplete. Indeed, pursuing the PostgresQL interface doesn't reveal any non-CA certificates until 1997, for www2.superb.net, which strongly suggests the records are simply incomplete.
To do further research, with a bit more effort, you might query the EFF's SSL Observatory database. Netcraft also alleges to have data about historical certificate trends, in exchange for money, but it's not clear that they have the actual certificates or just some summarized properties like what serial number and what type of key.