So I've scoured the net, and the short answer is "no".
There is however a Kernel#qualified_const_get
written by a "Gregory" which is kinda neat since it can get nested classes, but this obviously isn't native Ruby.
I found that little snippet from an awesome blog "Electric Sheep" by Sidu Ponnappa - who has done a magnificent writeup on using all three methods "Loading classes from strings in Ruby" - the conclusion being:
Here are three choices when trying to convert a string to the corresponding class: Kernel#const_get, eval and Kernel#qualified_const_get
Kernel#const_get is the fastest, doesn't handle nested classes and works for all but the weirdest of scenarios (the class you're trying to get hold of isn't a named constant)
eval is significantly slower, but it works in any situation
Kernel#qualified_const_get is abysmally slow, but handles nested classes. However, until there is a native implementation, it loses to eval on every front