We study property (T) and the fixed point property for actions on Lp and other Banach spaces. We show that property (T) holds when L2 is replaced by Lp (and even a subspace/quotient of Lp), and that in fact it is independent of 1 ≤ p < ∞. We show that the fixed point property for Lp follows from property (T) when 1 < p < 2+ε. For simple Lie groups and their lattices, we prove that the fixed point property for Lp holds for any 1 < p < ∞ if and only if the rank is at least two. Finally, we obtain a superrigidity result for actions of irreducible lattices in products of general groups on superreflexive Banach spaces.