WSP USA is the American arm of WSP Global, one of the largest engineering and professional services firms in the world, with U.S. headquarters in New York. The practice traces its lineage to 1885 through predecessor firms including Parsons Brinckerhoff, and works across transportation, bridges and tunnels, rail and transit, buildings, water, power and energy, environmental services and program management. WSP USA is the design partner alongside Walsh Construction on Rhode Island’s $339 million Washington Bridge replacement, a design-build project carrying Interstate 195 westbound over the Seekonk River that entered in-water construction in 2026 and is scheduled to open to traffic in November 2028. Parent company WSP Global has spent more than $5 billion acquiring U.S. power engineering firms since 2024.
One Penn Plaza in Midtown Manhattan is WSP USA’s head office, and the New York market is where the firm’s standing shows up most plainly: WSP topped Crain’s list of the largest engineering firms in New York in 2024 for the eighth consecutive year, a ranking built on the total number of licensed engineers on staff. The same year it placed second in Chicago.
Scale is the operative fact. WSP USA counts more than 15,500 employees across roughly 300 offices in the United States, which puts technical staff within reach of most projects rather than routing work through a few regional hubs. That U.S. organization sits inside WSP Global, a roughly 31,500-person firm working out of some 500 offices across 39 countries.
The service mix runs wider than design. WSP maintains a management consultancy and advisory practice covering transport and infrastructure, water, property and buildings, earth and environment, power and energy, industry, and mining and metals – work that lands upstream of drawings, in business cases, funding strategy and asset planning. A separate program and construction management arm carries projects through delivery. On the energy side the stated focus is decarbonization, with specialists in renewables, electrification, carbon capture usage and storage, and hydrogen utilization and storage.
The buildings practice is organized around the full project lifecycle, from early business planning through design and construction and on into asset management and renovation, with environmental, transport planning and infrastructure specialists attached to the same team. Public agencies draw on the water and environment side for waste management, water supply, flood control, green infrastructure, environmental remediation and socio-economic assessment.
Because the U.S. network is so large, the practical question for an owner evaluating WSP is which local office and which discipline leads would actually staff the job – the answer changes considerably by geography.