The Cray-1 (1976) was probably the first 64-bit CPU.
https://en.wikipedia.org/wiki/64-bit_computing#64-bit_data_t... names Stretch from 01961 as the first natively 64-bit CPU, but maybe there are some that are even older?
alt Hacker News
https://en.wikipedia.org/wiki/64-bit_computing#64-bit_data_t... names Stretch from 01961 as the first natively 64-bit CPU, but maybe there are some that are even older?