Region 4A
CALABARZON is composed by the provinces of Cavite, Laguna, Batangas, Rizal, and Quezon; the acronym is derived from the first two letters of every province that composes it.

The region is located in southwestern Luzon, just south and east of Metro Manila and is the second most densely populated region. CALABARZON and MIMAROPA were previously combined together as Southern Tagalog, until they were separated in 2002 by virtue of Executive Order No. 103. Executive Order No. 246, dated October 28, 2003, designated Calamba City as the regional center of CALABARZON. The largest city of CALABARZON Region and the second highly-urbanized city is Antipolo City, with Lucena City being the first. CALABARZON is the most populated region in the Philippines, with a population of 12,609,803 inhabitants.

The cities that make up CALABARZON are:

1. Batangas City

2. Lipa City

3. Tanauan City

4. Bacoor City

5. Cavite City

6. Dasmariñas City

7. Imus City

8. Tagaytay City

9. Trece Martires City

10. Biñan City

11. Cabuyao City

12. San Pablo City

13. Santa Rosa City

14. Lucena City

15. Tayabas City

16. Antipolo City

17. Calamba City