This move comes as Mainz sought to replace Brajan Gruda, who transferred to Brighton & Hove Albion earlier in the summer.
Gruda's departure had raised concerns about finding a suitable replacement, given his crucial role in Mainz's Bundesliga survival last season.
Vidovic, a promising Croatian U-21 international, is set to undergo a medical at Mainz later today before completing his move to the MEWA Arena.
The agreement includes an option for Mainz to buy Vidovic permanently for €5 million at the end of the season.
Despite his impending loan, Vidovic has extended his contract with Bayern Munich until 2026.
This new deal ensures that if Vidovic returns to Bayern after his loan spell, he will remain with the German champions until at least 2026.
Bayern Munich's honorary president has firmly dismissed the possibility of Nicolas Jackson making a permanent move from Chelsea, stating there's no way the striker will fulfill the required conditions for the transfer.
Bayern Munich's honorary president Uli Hoenes has been hyper cricital of Newcastle United's spending in the recently concluded transfer window, especially in regards to their purchase of Nick Woltemade from Stuttgart.
Cody Gakpo has opened up about the intense transfer speculation linking him to Bayern Munich, admitting the situation was "hectic and stressful" before ultimately deciding to extend his stay at Liverpool.
Luis Diaz has made a flying start to life at Bayern Munich after his high-profile move from Liverpool, with the Colombian winger quickly proving why the German champions fought hard to sign him.
