The racecourse, which is owned by Ayrshire businessmen Alan Macdonald, of Dawn Group, and Richard Johnstone, has refinanced for a five-year period. It was with Bank of Scotland previously.
Established in 1824, The Western Meeting Club Group's Ayr Racecourse hosts several high-profile races each year including the Ayr Gold Cup and Scottish Grand National. It attracts more than 40,000 visitors annually.
The Ayr Racecourse complex also caters for large corporate and conference events, as well as weddings at the Western House Hotel.
David Brown, managing director of Ayr Racecourse, said: "There has been a huge surge in interest in racing in recent years which has been matched by large sponsorship and increased media exposure, particularly TV and online platforms. We have been pursuing an ambitious programme of development and refurbishment at Ayr, which has allowed us to further enhance our existing services, while also allowing us to adapt to the fast-moving modern market.
"At Clydesdale Bank, we have been dealing with people who understand our business and the sector we work in, which has been a key factor in our decision to switch our banking."
More than £20m has been invested in the site since 2006 on "priority areas" including the Princess Royal Exhibition, Banqueting and Conference Centre. In the next five years, The Western Meeting Club aims to attract more visitors to Ayr Racecourse.
Mark Wilson, head of Clydesdale's business and private banking centre in Ayr, said: "Ayr Racecourse has been part of the fabric of the community for almost two centuries, and continues to evolve and meet the needs of the current market."