Pupils on Monday dressed in traditional Saudi apparel to mark Founding Day across schools in the kingdom.
Bakeries are creating special cakes for Founding Day, which is on Wednesday.
“My girls wore the jalabiya — the long Saudi dress and we took some customised Founding Day cupcakes for the class,” said Tala Hasan, a resident of Jeddah.
“Munch Bakery is doing great ones.”
Founding Day falls on February 22 and commemorates the establishment of the Saudi state.
This is its second year, and staff from the public and private sectors will have the day off work.
Public sector employees also have February 23 off, followed by the two-day weekend.
Landmarks around the kingdom will be the focus of celebrations.
“Expats in the kingdom are excited to witness the kingdom's change and progress,” said Fatima Khan, a Canadian who lives in Riyadh.
Public spaces like malls have been playing traditional Saudi songs, while shops are advertising special offers and selling Founding Day merchandise such as flags and other memorabilia.
“We plan to buy Founding Day flags and watch the fireworks with our kids,” Ms Khan said.
“I think it’s more important than any other holiday except Eid, of course.”
Saudi Arabia's Ministry of Culture has flooded social media with informative posts, while banners in streets around the kingdom build up the festive atmosphere.
“Fireworks and aircraft shows are our favourite. We plan to get ice cream and have a picnic by the corniche as all of us have long weekend and it’ll be great fun outdoors,” said Aya Hisham, a Saudi resident of Jeddah.
Celebratory theatre performances at Princess Nourah University in Riyadh will take place from February 22 until February 27.
“It’s a proud moment for Saudis, and we look forward to celebrating our national day together,” said Alanoud Albakr, a Saudi who lives in Riyadh.
“I will visit Diriyah, the birthplace of the kingdom, with my mum and sisters then head to the Bujairi Terrace for dinner afterwards.”
A horse parade and march will take place at Prince Turki bin Abdulaziz Al Awwal Road in Riyadh on February 24.
“It’s going to be packed this whole weekend because schools are off and so are parents, so it’s a great time to mark such a great occasion,” said Maha Ahmed, who lives in Riyadh.
“We will be going to the Riyadh Boulevard world to enjoy the festivities and weather.”