City Birthday Party

35th City Birthday Party

April 6, 2024 | 10 a.m.-4 p.m.

Summitridge Park and Diamond Bar Center

This April marks 35 years of cityhood for Diamond Bar! To commemorate this milestone, the City is planning a special community celebration packed with fun activities for the entire family. There will be live entertainment and demonstrations, games and attractions, food trucks, and a variety of vendors providing information and giveaways. The festive event will include the recognition and presentation of awards to several community volunteers. 

Join us at the lower stage for welcome and introductions as well as outstanding volunteer awards at 1 p.m. and a special birthday sweet treat at 1:30 p.m.

The day’s activities include:

  • Inflatable Attractions
  • Game Booths
  • Food Trucks
    • Vchos Truck (pupuseria)
    • Messi Burger
    • Milas Kitchen
    • Daddy's Best Froyo
  • Community Showcase
  • Business Expo
  • Environmental Services Area
  • Public Safety Displays
  • City History Display hosted by local historian Greg Busch
  • Crafts, Face Painting, and Entertainment
  • Photo booths
  • Outstanding Volunteer Awards

Celebrate the Diamond Bar Center's 20th Anniversary

Learn the Center's origins, take a guided tour of the facility's various rooms and event set-up displays!

Inflatable Attraction Wristbands and Game/Craft Activity Cards

  • $10 unlimited rides on inflatables
  • $1 Activity Card/4 activities for games and crafts

Wristbands and cards will be available for purchase at the event. Cash and credit cards accepted.

Expo and Showcase

Businesses and community groups are invited to host a booth as part of the Business Expo, Community Information area, or nominate someone who has positively contributed to the community as a Outstanding Volunteer. For more information, see below:

Business Expo

Expo Vendor Application deadline is Friday, March 8, 2024. Booth fee of $250 includes one six-foot table and two chairs within the Diamond Bar Center Grand View Ballroom. For questions, contact Recreation Supervisor Crystal Knox at (909) 839-7070 or email to Applications along with fees may be submitted by mail, in person or email. See application for complete rules and event details.

Community Information Booths

Diamond Bar based non-profit organizations, schools and churches may participate by submitting application along with $100 booth fee by Friday, March 15, 2024 to Recreation Specialist Jordan Herrera at or in-person at City Hall, located at 21810 Copley Drive. Booths will be located within the Diamond Bar Center Grand View Ballroom and consists of one six-foot table and two chairs, electricity is available for an additional cost. See Community Information Booth application for complete rules and event details. Applications along with fees may be submitted by mail, in person or email.

Outstanding Volunteer Nominations

Do you know someone who has demonstrated extraordinary acts of kindness or went out of their way to make life in Diamond Bar better? Help us recognize these individuals by nominating them to receive a special award. Nominations will be accepted until 5:30 p.m. on Monday, March 18, 2024 and must be made online by clicking the following link - Outstanding Volunteer Form

For questions, contact Community Relations Division at (909) 839-7055 or via email at .

Community Entertainment

Local performers are asked to submit applications to participate by Friday, March 8. Entertainment stage will be located in the lower grass area of the park with performances scheduled from 10 a.m. to 1 p.m. See Entertainment Application for complete details. For questions, contact Recreation Coordinator Jessica Rayela at (909) 839-7073 or via email at

Entertainment Applications may be submitted by mail, in person or email.

Parking and Shuttle

Free parking and shuttle to the event site will be available from Calvary Chapel located at 22324 Golden Springs Dr., Diamond Bar, CA 91765. Continuous shuttle service to and from the event will be provided starting at 9 a.m. until 6 p.m., handicapped shuttle service will also be available. 

For questions about the event, contact Recreation Coordinator Jessica Rayela at (909) 839-7073 or email at .