Missouri · Inground Pool Builders & Contractors · Updated 2026
Planning a permanent backyard pool? 19 inground pool builders serving O'Fallon, ranked by rating and review count, with what a fiberglass, gunite or vinyl liner pool costs installed in O'Fallon this year.
Ordered by customer rating and review count across the O'Fallon area. Listings include the available rating, contact details and location; confirm current credentials and scope directly.
Companies in the second group are listed as pool builders; most build inground pools in at least one material — ask which types they install and how many they completed last year.
Planning a new pool as well? The O'Fallon pool builders directory ranks all 39 builders in the area.
Installed prices in O'Fallon run from $43,000–$66,500 for a mid-size vinyl liner pool to $71,500–$114,000 for a comparable gunite pool, with fiberglass in between at $55,000–$81,000. Decking, fencing and permits stack on top:
| Job | Typical O'Fallon price |
|---|---|
| Vinyl liner pool, installed (about 16×32) | $43,000–$66,500 |
| Fiberglass pool, installed (about 14×30) | $55,000–$81,000 |
| Gunite / concrete pool, installed (about 16×32) | $71,500–$114,000 |
| Attached spa or spillover | $11,500–$33,500 |
| Decking and coping around the pool | $5,500–$19,000 |
| Safety fence and gates | $1,900–$5,700 |
| Permits, engineering, utility locates | $500–$3,300 |
| Typical all-in project with deck and fence | $66,500–$142,500+ |
| Ongoing upkeep (chemicals, power, service) | $1,200–$2,900 / year |
Missouri pricing is close to the national baseline used for these estimates. Soil, access for excavation equipment, slope, utility relocation and the finish and feature package move a quote more than the pool's footprint does — compare itemized bids for the same size and type.
Fiberglass, gunite and vinyl bids are not comparable to each other — settle the type (or ask each builder to bid two), then compare like for like.
O'Fallon market
4.2 average customer rating · 906 reviews · 19 companies · 15 specialists
See All on the Map →19 inground pool builders serving O'Fallon. 15 are listed as specialists for this work; the rest are pool builders that routinely handle it. The ranked companies average 4.2 stars across 906 customer reviews. PoolPad orders the list with a weighted score that combines customer rating and review count, so a long track record counts for more than a handful of scores.
Clay soils around both metros need drainage design and properly compacted backfill; the Ozarks add rock excavation that belongs in a written per-yard clause. Sloped lots in St. Louis County and lake areas often bring retaining walls into the bid. Vinyl liner and fiberglass carry the volume; gunite leads in the country-club corridors of both metros. Tanning ledges, firepits, and covered outdoor living are fully mainstream here.
For statewide rankings, city counts and Missouri prices, see the Missouri inground pool builders directory, or check the nearby cities below.
Get at least three itemized bids for the same type and size, visit finished pools that are a few years old, and read the warranty for the shell, the finish and the equipment separately. Ask how the company handles rock, groundwater and access problems once digging starts. Missouri handles residential contractor licensing at the city and county level, so check insurance certificates and references and confirm a licensed electrician handles the equipment permit. Pool permits and residential-code barrier requirements run through the municipality.
Installed in O'Fallon, MO, a mid-size vinyl liner pool typically runs $43,000–$66,500, a fiberglass pool $55,000–$81,000 and a gunite pool $71,500–$114,000. With decking, a fence and permits most complete projects land at $66,500–$142,500+. Missouri pricing is close to the national baseline used for these estimates; the size, finish, features and site conditions move the number most.
There is no single best type. Fiberglass installs fastest and is the easiest to maintain but comes in fixed shapes; gunite can be any shape with any feature but costs more to build and to resurface later; vinyl liner has the lowest upfront price but needs a new liner every eight to twelve years. Match the type to your budget, your yard, how long you plan to stay and how much maintenance you want.
A fiberglass pool is often swimmable two to six weeks after excavation; a vinyl liner pool four to eight weeks; a gunite pool eight to sixteen weeks because the shell has to cure before tile, coping and the finish go on. Permitting adds two to eight weeks up front, and decking and landscaping follow the pool. Most crews dig in the off-season so the pool is ready when the season opens.
Most residential pools are 3 to 6 feet with a deep end of 6 to 8 feet; diving depths of 8 feet or more need a longer pool and a larger excavation. Fiberglass shells are limited to the manufacturer's molds (commonly 6 to 8 feet), while gunite and vinyl liner pools can be built to almost any profile, including sport pools that are shallow at both ends.
The outdoor season in O'Fallon runs May through September — about 5 months unheated. A full professional winterization each fall protects plumbing and equipment through the freeze, and spring openings cluster into the same few weeks. May through September with hot, sticky midsummers that make the pool the family HQ. Winters freeze properly statewide, so October closes and April openings frame the year.
River Pools St. Louis has the highest customer rating on this O'Fallon list at 5 stars across 12 reviews. Prestige Pools & Spas has the largest review count (250 reviews at 4.5 stars). PoolPad orders the list with a weighted score that combines customer rating and review count, so a long track record counts for more than a handful of scores.
Missouri handles residential contractor licensing at the city and county level, so check insurance certificates and references and confirm a licensed electrician handles the equipment permit. Pool permits and residential-code barrier requirements run through the municipality.
Budget $1,200–$2,900 / year for chemicals, electricity and routine service, more for a heated pool or a weekly cleaning route. Fiberglass and vinyl surfaces use fewer chemicals than plaster; a variable-speed pump and an automatic cover cut running costs the most.
Check inground pool builders in cities near O'Fallon, or open the Missouri directory for every listed market in the state.
Claim your free PoolPad listing, check the pool types you build, and show O'Fallon homeowners planning a new pool what you install.
