As devastating wildfires continue to tear through neighborhoods across L.A., displaced residents are scrambling to find shelter -- but many are coming up empty-handed as the city's most well-known hotels are at full capacity ... TMZ has learned.

We've spoken to folks at several hotels across the city who tell us they've been fully booked since Tuesday afternoon, shortly after flames began ravaging the celeb-filled Pacific Palisades neighborhood.

Among them, The Peninsula Hotel in Beverly Hills has reached capacity. While a few cancelations had freed up rooms early on, those vacancies were immediately filled by evacuees seeking shelter. The hotel is offering a 10% discount to guests affected by the wildfires.

Other hotels -- including The Beverly Hills Hotel, Waldorf Astoria, Four Seasons, and SLS in Beverly Hills -- are completely booked as well. The Hotel Bel-Air is nearing capacity with potential guests facing a 30-minute wait time to speak with a reservations representative. The Ritz-Carlton in Marina del Rey has filled every available room.

The fires have destroyed thousands of acres of land and buildings, including properties owned by celebs. As flames continued to spread, a new blaze overnight in Pasadena prompted additional evacuations, adding to the tens of thousands of residents displaced throughout the L.A. area.

Officials have yet to determine the causes of the wildfires, which have left a trail of destruction and uncertainty in their wake.