Alex Trebek Donates $500k to New Homeless Shelter in San Fernando Valley

Alex Trebek dug deep into his pockets again to help a homeless shelter get a new facility off the ground -- more than doubling his previous donation for a very similar cause.

Ken Craft -- founder of Hope of the Valley Rescue Mission -- tells TMZ ... Alex handed over $500k of his own money to help Hope of the Valley with a brand new homeless shelter they're aiming to get built over the next year or so in the San Fernando Valley.

This new initiative is mega -- they're calling it Hope Central -- and we're told it'll be a 50,000-square-foot facility that'll house homeless seniors in the area. The team is currently scouting properties and will break ground in 2021 -- now, with much more ease thanks to Alex.

Now, bear in mind ... AT's latest donation comes on the heels of another generous move -- giving Hope of the Valley a $100k donation for another facility it's working on in North Hollywood.

We got pics of Alex and his wife, Jean, taking a stroll around the construction site Tuesday and touring the facility, which has a whole wing named after them. Specifically, the largest room in that building, the Alex and Jean Trebek Multi-Purpose Room, where people will eat and chill.

At some point in the day, Trebek and co. also toured another facility HOTV is building in Van Nuys -- and somewhere along the way, they were also seen hitting up a Home Depot nearby.

As for this latest donation, Ken tells us it brought him to tears. He also says the Trebeks told him they hoped it would spur others to donate/help out the homeless crisis.

Apparently, Alex and Jean feel society tends to write off people suffering from homelessness as nothing but drunks and addicts. They clearly don't feel that's the case though.