Allegis Group

The best staffing agencies that people actually use most often are the large, established brands that appear repeatedly across industry rankings: Randstad, Robert Half, Kelly Services, Adecco, ManpowerGroup, Kforce, Aerotek, Insight Global, TEKsystems, and Allegis Group.

If you want the most practical shortlist, these are the strongest picks by common use case:

• Robert Half — best known for finance, accounting, and professional office roles.
• Randstad — one of the most broadly used full-service staffing brands with large-scale coverage.
• Kelly Services — a top choice for job seekers across engineering, science, IT, education, and finance.
• Adecco — widely used for international and general staffing needs.
• ManpowerGroup / Manpower — a major brand for broad staffing and temp work.
• Kforce — strong for technology and specialized professional roles.
• Aerotek — commonly used for industrial, construction, and skilled trades hiring.
• Insight Global — frequently recommended for IT and professional staffing.
• TEKsystems — a leading choice for IT staffing.
• Allegis Group — a major staffing network often cited among the largest U.S. firms.

A simple way to choose:

• For finance/accounting: Robert Half.
• For IT/tech: TEKsystems, Insight Global, Kforce.
• For industrial/construction: Aerotek, TrueBlue, Staffmark.
• For general temp or high-volume hiring: Randstad, Adecco, ManpowerGroup.
• For broad job-seeker support: Kelly Services.

If you want, I can also give you a ranked top 10 by category for either job seekers or employers.

The top staffing agencies by actual usage and popularity are the largest firms by revenue (indicating high volume of placements and client adoption) and those frequently recommended in independent surveys like Forbes’ annual rankings (based on input from recruiters, HR managers, hiring managers, and candidates).

These draw from Staffing Industry Analysts (SIA) data on 2025 US staffing revenue and global rankings, plus Forbes lists emphasizing real-world recommendations. “Best” depends on your needs (e.g., industry, temp/contract vs. permanent, location), but the following stand out for broad use and recognition.

Top Overall/High-Volume Agencies

These handle massive scale across industries:

• Robert Half — Frequently ranks #1 in professional recruiting (finance, accounting, legal, admin, tech). Strong for contract/temp and permanent roles; consistently tops or near-tops Forbes lists due to high client and peer recommendations.
• Kelly Services — Broad coverage (engineering, science, IT, education, finance, admin, light industrial). Often #2 on professional and temp staffing lists in Forbes surveys; praised for industry-experienced recruiters and Fortune 500 access.
• Randstad — Global leader (often #1 worldwide by revenue) with strong US presence in professional, IT, engineering, industrial, and healthcare staffing. High volume and consistent top-5 Forbes temp staffing ranking.
• ManpowerGroup (including Manpower and Experis brands) — Major player in industrial, professional, and IT staffing; frequently #1 or top-tier in temp staffing rankings.
• Allegis Group (brands include TEKsystems for IT, Aerotek for industrial/engineering/skilled trades, Aston Carter for finance/professional) — Largest or near-largest US staffing firm by revenue (~$9B+); dominant in IT and industrial segments.

Strong Specialists by Sector

• Insight Global — Top for IT and professional services/contract staffing (often top 3–5 by US revenue).
• Adecco — Global powerhouse with broad multi-industry staffing; regular top-5 in Forbes temp/professional lists.
• Express Employment Professionals — Popular for small/mid-size businesses, industrial, office/clerical, and light industrial roles; high US revenue ranking.
• Aya Healthcare (and peers like CHG Healthcare or Jackson Healthcare) — Dominant in healthcare/travel nursing/locum tenens (often #2 overall US by revenue).

Key Context and Tips

• Revenue leaders (SIA data) reflect real-world usage volume, as larger firms place far more workers annually. The biggest US firms generated tens of billions collectively.
• Forbes rankings prioritize peer/client recommendations over pure size, highlighting service quality.
• Other notables include Kforce (IT/finance), PeopleReady (on-demand industrial), and niche players for specific needs like remote/virtual roles or creative fields.
• Agencies typically charge clients (not job seekers). Focus on your industry/specialty for the best fit—e.g., Robert Half for finance pros, Aerotek/Express for trades/industrial, Aya for nurses.
• Experiences vary by local office/division; check recent client reviews, Glassdoor, or ClearlyRated “Best of Staffing” awards for specifics.

For employers or job seekers, start with these established brands as they dominate placements and have the broadest networks. Match to your exact requirements (e.g., contract vs. direct hire, location) for optimal results.