Where to Find the Best Growth Marketing Consultants in London (and what to look for)

For founders and CEOs who are ready to grow but unsure who to trust with their marketing.

The Challenge

If you’re leading a startup or scaleup in London, you’ve probably hit that moment when your growth plateaus, and suddenly everyone tells you to “hire a Head of Growth.” But what does that actually mean? Do you need performance marketing, brand strategy, lead generation, or someone to manage a full marketing team?

Finding the right growth marketing consultant can feel confusing, and hiring the wrong one is expensive. This guide breaks down where to find them, what to look for, and how to choose the right fit for your business.

What Does a Growth Marketing Consultant Actually Do?

A good growth marketing consultant blends creativity, commercial strategy, and data-driven testing to accelerate business growth. Unlike traditional agencies focused only on ads or creative, they help you:

• Identify the levers that drive your revenue growth

• Build a joined-up brand and acquisition strategy

• Shape your marketing team or agency structure

• Develop campaigns that convert (not just attract clicks)

• Set KPIs that align with business goals

At OSER, we call this “strategic growth in action”, thinking like a CMO, but delivering results that scale immediately.

Where to Find Growth Marketing Consultants in London

London has one of the most competitive marketing ecosystems in Europe, from performance agencies in Shoreditch to independent consultants and fractional CMOs. Here’s where to look:

1. Specialist Growth Consultancies – Companies like OSER focus on combining brand strategy, digital acquisition, and commercial alignment. These partners bring both creative and strategic firepower.

2. Fractional CMOs / Advisory Firms – Perfect for founders who need senior-level clarity before hiring. OSER’s CMO Advisory offers this model, short, high-impact strategy sessions to define exactly what kind of marketing your business needs.

3. Independent Consultants – Ideal for specific projects like lead generation or PPC campaigns, but often less holistic.

4. Venture or Accelerator Networks – Many VCs and accelerators keep trusted consultant lists, often with operators who have scaled similar startups before.

5. Referrals from Founders – Still the most powerful way. Ask peers in your network who they’ve used for strategy, brand, or growth.

What to Look for in a Growth Marketing Partner

Before signing anything, look beyond credentials. The best partners:

• Understand your business model and customer journey

• Balance brand strategy with performance execution

• Can explain their growth framework clearly (not hide behind jargon)

• Have experience across channels (not just paid social or PPC)

• Can help design or advise your internal marketing structure

• Align marketing activity directly to revenue and commercial goals

At OSER, we start every engagement with clarity - what the business actually needs to grow - before deciding on the tools or tactics to use.

How to Choose the Right Consultant for Your Stage

Different growth stages need different marketing minds:

Stage	What You Need	Who to Hire
Pre-Seed / Early Stage	Positioning, story, and validation	Brand strategist or part-time CMO
Seed to Series A	Channel testing and scalable systems	Growth marketing consultant or hybrid strategist
Series B+ / Scaleup	Team leadership, cross-channel strategy, investor alignment	Fractional CMO or marketing director-level partner

If you’re unsure where you fit, I would advise starting small. A one-hour CMO Advisory session can save months of trial and error.

Why Founders Choose OSER

OSER works with founders, CEOs, and investors who want marketing to deliver measurable growth, not vanity metrics.

We blend:

• Strategy: brand clarity and commercial focus

• Planning: practical activation roadmaps

• Execution: creative campaigns and performance systems that scale

Our clients range from funded startups to mid-size scaleups and investor-backed ventures across the UK. We’re based in London but work globally with growth-driven teams.

Get Clarity Before You Hire

If you’re deciding whether to hire a Head of Marketing, agency, or in-house team, why not start here?

Book an OSER CMO Advisory session to define what kind of marketing leader and structure your business actually needs. You’ll leave with clear next steps, a strategic roadmap, and confidence in your growth direction.

→ Book a 60-Minute Advisory Session

Book a 1 x Hour Advisory Call

FAQs

What’s the difference between a growth marketing consultant and a marketing agency? A consultant helps define what to do and why, setting the strategy. An agency focuses on doing the work (ads, creative, content). OSER bridges both.

How much do growth marketing consultants charge in London? Typically between £100–£250/hour, or £2,000–£5,000/month for advisory retainers. OSER’s CMO Advisory sessions start at £500.

Can growth marketing consultants help with hiring or team setup? Yes - senior consultants, like those at OSER, often design marketing organisation structures, help define roles, and support hiring the right talent.