According to the Saudi Ministry of Interior, joint operations were conducted in cooperation with relevant government agencies between October 1 and 7.
Of those arrested, 6,785 were detained for violating residency regulations, 3,710 on suspicion of breaching border security laws, and 3,394 for labour law violations.
Authorities also arrested 1,382 people who allegedly attempted to enter Saudi Arabia illegally across its borders. Of these, 66 per cent were Ethiopian nationals, 33 per cent were Yemeni nationals, and one per cent were from other countries. Another 34 people were detained for attempting to leave the kingdom illegally.
The ministry said legal proceedings were underway against 33,113 foreign nationals over residency and immigration violations, including 30,438 men and 2,675 women.
Officials added that 18,947 people had been referred to their respective diplomatic missions to obtain travel documents, while 4,596 others were referred to the relevant authorities to complete arrangements for their return home.
Authorities also arrested 21 people accused of providing transportation, accommodation or employment to individuals residing in the country illegally.
The Saudi Ministry of Interior warned that anyone who facilitates illegal entry, transports or shelters undocumented residents, or otherwise assists them could face severe penalties.
Offenders may receive prison sentences of up to 15 years and fines of up to 1 million Saudi riyals. Vehicles used for transporting illegal residents and properties used to shelter them may also be confiscated.
The ministry urged citizens and residents to report violations to the relevant authorities. Reports can be made through the 911 emergency hotline in Makkah, Riyadh and the Eastern Province.