Listed below are the (current) set of courses on theoretical physics courtesy of Stanford University. The lecturer is Professor Leonard Susskind, an eminent theoretical physicist and one of the founding fathers of string theory. A profile of Professor Susskind is available on Wikipedia.
These lectures can be considered to be - and are sometimes referred to as - the Theoretical Minimum, meaning that the material covered in each course is the minimum that could be taught in order to define and use key concepts of modern physics.
I suppose it would be possible to complete some of these courses without a good mathematical grounding, but I imagine a reasonable knowledge of algebra, geometry and calculus is pretty much required to understand most of the lectures. Professor Susskind also assumes a knowledge of Newton's laws of motion.
Nb. People struggling with the necessary mathematical skills might want to try Professor Walter Lewin's lectures on classical physics first.
(Known as Quantum Entanglements Part 3)
|Classical Field Theory
(Known as Special Relativity)
(Known as Einstein's Theory)
(Known as Quantum Entanglements Part 1)
|Particle Physics: Basic Concepts||0/10|
|Particle Physics: Standard Model||0/10|
|Particle Physics: Supersymmetry
(Known as Supersymmetry, Grand Unifications and String Theory)
|String Theory and M-Theory||0/10|
|Topics in String Theory||0/9|