Does an SSL need a Dedicated IP Address?Short Answer: No, not at all.
Long Answer: SSL was released in the 90's when every website had its own IP address, at the time an SSL certificate was tied to an IP address for this reason. Around the year 2000 we started running out of available IP addresses and a technology called virtual hosts was invented to allow multiple websites to share the same IP address, but still be recognised as individual websites by the internet. Another technology called SNI (Server Name Indication) followed this, SNI allowed websites to have their own SSL certificate without the need for a dedicated IP address. While SNI was released in 2006 it only came into common use in 2011 when CentOS (the Operating System that runs most web servers) began to support the technology.
You can read more about SNI here: https://en.wikipedia.org/wiki/Transport_Layer_Security#SSL_1.0,_2.0_and_3.0