The 26-year-old has become a key figure since initially joining on loan from Sheffield United in 2020.
“I’m delighted. From the first second I arrived, I’ve never kept it a secret how much I’ve enjoyed my time since being here. It’s a good place to come in, so I enjoy it here, to say the least.
“I feel really grateful to the club for the opportunity they gave me. I’m proud of what I’ve achieved here, and hopefully, there’s more to come. I have unbelievable memories with unbelievable people.
“Last season was probably the best time of my life, especially afterwards when we had actually done it. The celebrations were unbelievable – I’d love to do that every week.”
Slater has made 234 appearances for the Tigers, scoring 11 goals, and helped secure two promotions.
He was named both Players’ and Supporters’ Player of the Year for 2022/23 and again last season.