The Championship football club has reported the deal as the biggest shirt sponsorship in its history.
Football Index is a platform which allows traders to buy and sell shares in professional footballers, providing fans with the opportunity to bet on the future success of a player.
This is Football Index’s second partnership with a football club, having previously sponsored Bristol Rovers.
Nottingham Forest’s previous sponsor, BetBright, ceased its gambling services last season.
The operator sold its betting platform for £15m ($19.9m) to 888 Holdings, another previous shirt sponsor of Nottingham Forest.
Neil Kelly, CEO of BetIndex Ltd, Football Index’s parent company, said: “We’re thrilled to have Football Index front and centre on the new Nottingham Forest kit – a club steeped in history with an expansive and proud fanbase.”
Nottingham Forest’s CCO, David Cook, commented: “Across the partnership, we look forward to offering fans some great benefits and incentives whilst providing a strong platform for Football Index to achieve their marketing objectives.”
