
The deal will run over five years and comes two weeks after the opening of the Duchess Stand as part of a £38m redevelopment.
Investec is already the title sponsor of the annual autumn rugby union series, the Investec Challenge which pits the England team against southern hemisphere nations.
The Derby had faced the possibility of running without a title sponsor for the first time in many years following Vodafone's decision to pull out after 14 years. Vodafone had replaced Ever Ready in 1984.