Pentium was the first CPU with a branch predictor that many people could afford to buy.

Before dynamic branch prediction, where the prediction for every branch is updated after each branch execution, depending on its history, static branch prediction had been used for decades, since around 1960, typically using the rule that forwards branches are unlikely to be taken, but backwards branches are likely to be taken. An alternative was to have an instruction bit where the compiler stored its prediction about the probability of a branch being taken.

Dynamic branch predictors began to be used since the mid seventies.

I do not remember now if any notable monolithic CPU had a dynamic branch predictor before Pentium, but prior multi-chip CPUs certainly existed.