Things named after an American mathematician John Milnor:
Fary–Milnor theorem
Milnor conjecture in algebraic K-theory
Milnor conjecture in knot theory
Milnor conjecture concerning manifolds with nonnegative Ricci curvature
Milnor construction
Milnor K-theory
Milnor fibration
Milnor map
Milnor number
Milnor ring
Milnor sphere
Milnor theorem
Milnor–Thurston kneading theory
Milnor Frame concerning left invariant metrics on three-dimensional Lie groups