32Red, part of Kindred Group, has been Leeds' front-of- shirt sponsor for the past three seasons.
Unibet, also owned by Kindred, will be the match kit sponsor for the club's pre-season tour of Australia and will feature on the club's new training kit.
The extension will allow Kindred to continue to hold exclusive betting rights at Leeds.
Last season, 32Red sponsored four other Championship clubs; Aston Villa, Middlesbrough, Preston North End and Derby County.
Leeds United Executive Director Paul Bell said: “We are pleased to continue our journey with 32Red. We have exciting plans for the rest of our centenary season and we are thrilled that 32Red will be involved in what we hope will be a historic kit.”
Kindred's General Manager Neil Banbury said: “We are committed to reinventing the sports sponsorship model, so it benefits the entire community and we look forward to working with Leeds through both our 32Red and Unibet brands."
