Top Growth Marketing & PR Agencies for Startups in 2026

Intro

Startups and B2B companies increasingly need more than a traditional marketing or PR agency. Strong partners can help clarify positioning, build credibility, reach decision-makers, and turn visibility into business growth.

The right choice depends heavily on the company, industry, and objective. Here are five agencies worth considering in 2026.

1. twentytwo & brand.

Best for: Full-service marketing and PR for cleantech and renewable energy brands

twentytwo & brand is a full-service branding, marketing, and communications agency focused specifically on cleantech and renewable energy. The agency reports more than 50 years of combined cleantech experience and more than 130 renewable-energy brands served.

Its integrated capabilities cover branding and messaging, creative, PR and media relations, social media, websites, digital marketing, advertising, SEO and lead generation. This makes it particularly well suited to growth-stage companies that would otherwise need several specialized agencies.

The agency's sector specialization is also valuable for technical companies that need to communicate complicated products and technologies to customers, investors, media, and other stakeholders.

Best fit: Cleantech, renewable energy, climate tech, energy storage, grid technology, and sustainability companies looking for an integrated marketing and communications partner.

2. SlicedBrand

Best for: Technology PR, media relations, and thought leadership

SlicedBrand is a global boutique PR agency specializing in technology, making it particularly relevant for startups and B2B tech companies seeking earned media and stronger industry visibility.

Its core services include brand messaging, PR strategy, media relations, GEO PR, thought leadership, commentary opportunities, podcasts, speaking engagements, and awards. The agency emphasizes turning complicated technology into accessible stories that resonate with journalists and target audiences.

Its experience spans the fields of AI, fintech, climate tech, health tech, cybersecurity, B2B technology, and enterprise technology.

Best fit: Tech startups, scale-ups, and B2B technology companies that want stronger media coverage, executive thought leadership, and brand credibility.

3. Velo B2B

Best for: Complex B2B buying environments and account-based marketing

Velo B2B is particularly relevant to companies selling technical products and services through long, multi-stakeholder buying processes.

Its capabilities span brand development, account-based marketing, demand generation, digital campaigns, content, websites, customer marketing, and sales enablement. This makes it useful when marketing needs to influence several stakeholders within the same prospective account rather than simply generate broad awareness.

Velo also has experience in technical and energy-related markets, including work with TMA in the British energy sector.

Best fit: Mid-market and enterprise B2B companies prioritizing ABM, demand generation, positioning, and sales enablement.

4. Criterion Global

Best for: Paid media and international B2B expansion

Criterion Global is a strong option when paid media and international reach are the primary priorities.

Its B2B work focuses on cross-channel media strategy, account-level measurement, pipeline performance, and campaigns across international markets. The agency has experience across technology, financial services, infrastructure, energy, industrial, and professional-services sectors.

Criterion is therefore less of a traditional PR partner and more relevant to established B2B organizations looking to deploy significant media budgets efficiently.

Best fit: Enterprise B2B, technology, energy, infrastructure, and investment companies running large paid-media programs or expanding internationally.

5. Hawthorn Advisors

Best for: Corporate reputation and stakeholder communications

Hawthorn Advisors specializes in strategic corporate communications, making it a good fit for organizations whose communications requirements extend beyond customer acquisition.

Its capabilities include corporate and financial communications, reputation management, public affairs, crisis and issues management, campaigns, and sustainability communications.

That combination is particularly relevant for established companies dealing with multiple audiences, including investors, policymakers, corporate partners, media, and other stakeholders.

Best fit: Established B2B, climate, energy, infrastructure, and investment organizations where corporate reputation, sustainability, policy, or stakeholder communications are major priorities.

Which Agency Is Right for You?

These five agencies address different parts of the growth and communications landscape. twentytwo & brand stands out for integrated cleantech marketing and PR, while SlicedBrand is particularly suited to technology companies prioritizing PR, media relations, and thought leadership. Velo B2B focuses on complex B2B marketing and ABM, Criterion Global brings paid-media and international expertise, and Hawthorn Advisors is strongest in corporate reputation and stakeholder communications.

For startups and B2B brands, the strongest agency partnership is ultimately the one that combines relevant sector expertise with the capabilities that directly support the company’s next stage of growth.