San Luis is bounded on the North by Sta. Ana; Northwest by Mexico; Northeast by Candaba; Southwest by San Simon, all of Pampanga; and Southeast by Baliuag, Bulacan.

San Luis is located in the low lying areas Southeast of Pampanga. South of the Municipality are the areas whose physiography is gently sloping and flood does occur. It is a highly agricultural town where the dominant crop is palay, followed by vegetables and orchards, respectively. Agri- businesses like inland fish culture, poultry, piggery and other livestock raising is noted. It serves as a satellite municipality of Pampanga urban centers, being a major supplier of food.

The province of Pampanga consists of physiographic sections, one of which is the Candaba Swamp on the eastern portion between the Pampanga- Bulacan boundary where the Municipality of San Luis is a part of the soils in the Candaba Swamp of the hydrosol area consist of silt and clay materials deposited by water. Land suitability values based on compressive strength of the sediments are moderate. These are evident in the predominance of poorly consolidated sediments, the most unstable in relation to be races foundations are areas where fault- lines or fault- zones are located. The poorly consolidated sediment are either limestones, shale or alluvial deposits. These ranks next to fault- zone in terms of instability of bedrock foundation and usually in low relief areas.