LA County Library - Diamond Bar Library *June 30th, 2026…read more*10:00am-5:00pm - Tuesday *4 Stars Environment: *Moderate Sized Parking Lot *Helpful Staff *Average Seating Available Went here with a friend to get some work done and overall had a good experience. The staff was very friendly, and the library was clean and well maintained. I was actually surprised by how busy it was for the summer, with people of all ages using the library throughout the day. My friend and I were hoping to use one of the private study rooms, but they were all booked. For anyone planning to go, you can reserve a study room up to one week in advance for a maximum of two hours per reservation. We were a little disappointed that we couldn't reserve a room until later in the afternoon, but luckily we arrived right when the library opened and were able to find a table. One thing I wish the library would consider is allowing walk-in use of reserved study rooms if the reservation becomes a no-show. The room we wanted sat empty for the first hour we were there, and it would have been nice if someone else could have used the space instead. Overall, it's a nice place to get work done with plenty of natural light and a good atmosphere, although I do wish the chairs were a little more comfortable for longer study sessions.

I originally discovered Diamond Bar Library while searching for a quieter place to study after…read morespending time at the West Covina Library. I still remember the first day I walked in here. The difference was immediate. The atmosphere felt calm, focused, and peaceful. It honestly felt like stepping into study heaven. For anyone who needs a consistently quiet environment to work or study, this has easily been one of the quietest libraries I've experienced in Los Angeles County. I spent many long hours here preparing for my medical board exams, so I really came to appreciate the environment. The layout offers a great mix of larger tables and individual study cubbies, and there are outlets available which makes settling in for long study sessions much easier. The library also feels very safe, likely because of its location next to City Hall and the fact that it sits a bit tucked away from the busiest parts of town. There are entrances in both the front and back, and I personally found the quieter seating area on the left side when entering from the back to be my favorite spot, especially the tables near the windows where you still get that nice natural light during the day. The staff has always been friendly and helpful as well. I believe one of the librarians named Jen really helped maintain a welcoming atmosphere. One thing I appreciate about this location is that they take maintaining a focused study environment seriously. For example, eating isn't allowed inside the library, which helps keep things clean and minimizes distractions. There is a garden area outside and you can always step outside for a quick snack break. After spending many hours here, I started to notice some of the daily rhythms of the building. The restrooms are impressively clean, which deserves a shout out to whoever keeps them maintained. The library also has a small bookstore run separately from the library itself, which is a fun little feature if you happen to stop by while it's open. If there were a few small improvements that could make an already great space even better, they would mostly relate to sound consistency. Because this is such a quiet library overall, small sounds can stand out more than they normally would. Occasionally conversations at the service desks or phones ringing can carry across the room, and sometimes outside maintenance work can be heard from the garden area. Nothing that ruins the experience, but little adjustments there could make an already peaceful environment even more ideal for studying. I also noticed that the closing announcements can be a bit startling if you're deep in concentration, so maybe a softer chime before the announcement could make it feel a bit smoother. Another thing that could help maintain the quiet atmosphere is occasionally reminding visitors with young children that certain sections are intended for quiet study. The kids' area is nicely separated, which already helps a lot, and a gentle reminder here and there would probably keep everything running smoothly. Overall, I'm genuinely grateful for this library. The long hours are fantastic. Being open until the evening made it possible for me to have full study days here when preparing for my boards. Yes, it was a bit of a drive from West Covina, but it was absolutely worth it for the calm environment and the ability to truly focus. Diamond Bar Library became one of my go to study spots, and it's a place I'll definitely remember fondly.

This place is a good library. It is quiet, and doing my homework here is peaceful with no…read moredistractions. The downside is it is very small. I hate the fact that they don't even have the books I want sometimes and it is just frustrating to come here and think "Maybe they don't have it here." Overall, this is an OK library, I mean not the best but if I really have to go here, I would.

Nice library, but not too spacious. The availability of books and other media is good, but the…read moreenvironment for reading and studying for patrons is not great. During the week it appears to be overpacked with kids. Not a bad thing, but they get noisy. I get it, kids need a place to go when parents are at work, but it's still a library.

Overall great location. I came to study and it was extremely noisy I couldn't focus, kids were…read morerunning around. It would've been a better experience if the noise level was down

Use to go as a kid. Pretty cool place. Library pretty cool too and service is pretty niceread more

Beautiful and quite large library. One of the cleaner LA libraries I've been to, with plenty of…read moreparking. We came for a kids' event that taught about poison in animals and also had a bunch of reptiles on display to see. They also host a ton of different popular events at this library, so I'd definitely come back to check those out.

This bookstore is located inside the Diamond Bar Library (by the self-checkout stations). The…read moreselection of books in this bookstore is incredible. The books are categorized by genres. The shelves at the back of the store contains the books that are part of the $5 sale (fill up the plastic bag with as many books as you want for $5). The newer books are by the shelf closest to the cashier. I got some (almost) brand new books ranging from $2-$4.

5 stars for the children's program! We attend the younger kids program ages 0-5 and the staff do an…read moreamazing job at keeping the kids engaged with song, dance, books, and crafts! They also have events throughout the year with more crafts, games, balloons and airbrush tattoos. Special shoutout to Ms. Dani, who brings such incredible energy to every class!! She's super animated and enthusiastic when engaging with the kids which really makes the program that much more special.

This library is very convenient and offers a great place to meet and research individually or as a…read moregroup.

Man, I really love Cal Poly's school library. My brother attended this University, and a few of my…read moreold friends graduated here. I used to also help friends study here. It's a big library with lots of books, computers, old magazines, and up to date magazines. Very very huge place to study. Nice professional staff to help out too. It's a awesome place to study.

I'm a current student at Cal Poly and I always study here whenever I'm on campus. The library is…read morehuge and has six floors that students can study at or find research. In addition, study rooms are available but they have to be booked and reserved ahead of time. If you seek really quiet or near-isolated areas, the 5th and 6th floors are the places to go. Wi-Fi is complimentary in the library and I believe that you can also eat/drink inside. (Or at least that's what I do, haha). The amount and supply of library books and research materials are endless and superfluous. If you are a student who is looking into borrowing physical hard copies to support your research, I highly recommend the library. The library also has flexible and long hours that can stretch late into the night, which is perfect for those who are staying in to study.

Great library! It offers computer access and a wide selection of books to enjoy. I really…read moreappreciate the seating with outlets--it makes getting work done much easier (see photo for reference). The only downside was that my seat didn't have a table to go with the outlet, though that was totally my choice haha. It is on the smaller side, and you'll need to park in an underground garage and take the elevator up to reach it.

Haven't been here in a little while, love this Library. I used to take baby girl here when she was…read morea baby for story time and play time was so much fun. Came here with my best friend her son and baby girl after school to check out some new books to read together. I used to just buy books but got overwhelmed with so many that it's easier just to rent a book plus gives us a reason to read new ones together. All the employees are really friendly. My friend had to get a library card I already had one so checked out 3 books. Usually park underground the lot is always full but found handicap thank goodness near the elevators. Nice courtyard they do tree lighting near here too during Christmas time. It's a cute little area for the library. Return book time is 3 weeks which is nice. Thank you for your help in finding books and for your friendly smiles. Baby girl and I also found a puzzle on the table we were trying to do for a bit too. Love this library. Have a beautiful day, thank you for the beautiful books and friendliness. :) Aloha

I love the online book hold system--so convenient: 1. sign…read morein using your library card number and your passcode, 2. look up the book you're interested in, 3. it'll tell you if any copies are available 4. Request hold, then you'll get an email when it's ready for pickup. 5. Go in during business hours and pick up the book! 6. Staff at the library are friendly and helpful too! Of course browsing in person is best, but when you're busy then this is a good alternative (especially when friends are recommending books to you). Picked up a book today and it was a breeze. Took 7 minutes from parking to picking up to leaving for home. :)

Lovely walk from Downtown Pomona, and can't wait to see the new park open and have the fountain up…read moreand running again! Great staff, always a delight and front desk staff especially, always helpful and polite, and just love the book recommendations every time I go! A staff that reads is a good employee indeed :) Looks like it will be a good summer here at the library!!

I like the flexibility of the hours to use when needed. However, this lab needs to be revamped…read more This is an old school with torn/worn down furniture that should be replaced

It IS OPEN 24 HOURS! Well, that's a no brainer! It is relatively clean, but always seems to smell…read morelike food whether that be bananas, Panda Express, coffee, burgers and fries, or sometimes all of those things a once! Yuck, I know. There is Wi-Fi available just in case you cannot snag a computer. There are two a bathrooms--one for the gentlemen and one for the lovely maidens. Give this place a try instead of staying at home or in your dorm. Oh, I almost forgot: 1. A valid student I.D. is need for access 2. You can print, but you must need to put money on your account beforehand via the Pharos system, which is located upstairs in the library. Do it ahead of time or else your S.O.L. if or when the library closes. 3. Food is not allowed, but meh, who cares? 4. Study long and hard!

Greatest place to work! Love working with students. We help a…read moreStudents from across the country. We do our best at helping the students with their research. It has been a rewarding experience.