Directory

Silicon Milkroundabout

CommunityOtherBritish

Silicon Milkroundabout is the UK's largest tech jobs fair, held biannually in London and connecting mid-to-senior technology professionals with startups and scaleups. Founded in 2011, the free-to-attend event has introduced over 100,000 job seekers to companies including Monzo, Snap and DeepMind. Events cover engineering, product, design and data roles.

Silver Lake

PESaaSAIForeign

Silver Lake is a global technology-focused private equity and growth equity firm founded in 1999, managing approximately $114 billion in assets as of 2026. The firm invests in mature and growth-stage technology and technology-enabled companies across software, semiconductors, fintech, e-commerce, and digital media, with a European office in London.

Silverfleet Capital

PEOtherConsumerBritish

Silverfleet Capital is an independent, partner-owned European mid-market private equity firm established in 2006 as a spinout from Prudential plc's private equity arm (formerly PPM Capital), with roots dating back to 1985. The firm specialises in buyouts of companies with an enterprise value of €25 million to €300 million across healthcare, business services, consumer, and manufacturing sectors, and has been focused on portfolio realisation since abandoning its third-fund raise in 2021.

Silverfort

ScaleupCybersecurityForeign

Discover and protect every dimension of identity, everywhere. Human, machine or AI, cloud or on-prem—including systems that couldn’t be protected before.

SimilarWeb

CorporateSaaSForeign

Similarweb is an AI-powered digital data company providing real-time market intelligence, competitive insights, and consumer trends to accelerate business growth.

Simmons & Simmons

Professional ServicesLegalBritish

Simmons & Simmons LLP is an international law firm founded in London in 1896, serving clients across financial institutions, technology, healthcare and life sciences, asset management, and energy sectors. The firm employs approximately 2,900 people across more than 20 offices in Europe, Asia, the Middle East, and the US.

Singular

VCOtherForeign

European early-stage VC firm investing from Seed to Series B in founders with global ambitions across all sectors, with offices in Paris and London.

Singular Photonics

StartupDeep TechBritish

Singular Photonics is a University of Edinburgh spinout and fabless semiconductor company developing single-photon avalanche diode (SPAD) based image sensors with on-chip computation for scientific, medical and industrial imaging applications.

Sitemate

ScaleupProptechAIForeign

Sitemate is the #1 front line AI company for the built world. We turn voice, photos, and conversations into structured, compliant records, automatically.

Sitetracker

ScaleupSaaSClimateForeign

Purpose-built for critical infrastructure, Sitetracker centralizes data, standardizes workflows and optimizes resources, driving efficiency and scalable growth.

Sixth Element Capital

VCBiotech & Life SciencesFinanceBritish

Sixth Element Capital (6EC) is a specialist UK venture capital fund manager focused exclusively on oncology. It manages the £70 million CRT Pioneer Fund, a dedicated oncology investment fund established in 2012 to bridge the gap between cancer drug discovery and early clinical development in Europe.

Skai

ScaleupMediaAIForeign

Unify retail, search, and social advertising with Skai’s AI-powered commerce media platform. Drive smarter, connected growth.

Skin Analytics

ScaleupBiotech & Life SciencesAIBritish

Developer of DERM, an autonomous AI medical device for skin cancer detection (CE Class III / UKCA Class IIa), deployed across NHS dermatology pathways.

SkinScanner.gg

StartupGamingBritish

Skinscanner.gg lets you compare CS2 skin prices across every marketplace in real time. Free, no login required. Find the best deal before you buy or sell.

Skyports

ScaleupLogisticsBritish

Builds and operates vertiports and runs autonomous drone-delivery and inspection services for advanced air mobility, combining eVTOL infrastructure development with commercial drone operations.

Skyral

ScaleupDefenceAIBritish

Modelling and simulation / synthetic-environment platform combining digital-twin modelling with AI; serves UK MOD, NATO, Raytheon, and Microsoft.

Skyscanner

CorporateConsumerE-commerceBritish

Compare cheap flight prices from all major airlines and travel agents, and find the cheapest tickets to all your favourite destinations. Book online today.

Slalom

Professional ServicesOtherAIForeign

Slalom is a global business and technology consulting firm founded in 2001 and headquartered in Seattle, with offices in the UK and across North America, Europe, Asia-Pacific, and Latin America. The firm provides services in strategy, artificial intelligence, cloud, data engineering, digital product development, and organisational change management.

Slingshot AI

StartupBiotech & Life SciencesDeep TechForeign

Slingshot AI is a mental health research lab building a foundation model for psychology. Our mission is to use AI to make mental health care more accessible, and to help people change their minds and lives the way they want to.

Smart Anchor Ventures

VCOtherBritish

Smart Anchor Ventures is a Cardiff-based investor that partners with entrepreneurial founders of innovative, technology-enabled companies in Wales and the UK, offering capital and experience to help businesses scale globally. The firm is sector-agnostic but favours companies that can differentiate through technology.

Smart Pension

CorporateFinanceBritish

Cloud-based retirement savings and pensions platform (Keystone) for employers and providers globally; one of the UK's largest DC master trusts with over £8.5 billion in assets under management.

Smartcat

ScaleupAISaaSForeign

Smartcat is your all-in-one AI translation platform with industry-leading AI translation, AI localization, AI content generation, and AI-human workflows.

SmartestEnergy

ScaleupClimateBritish

Independent B2B energy supplier and trader that buys, sells and trades renewable power for businesses and independent generators.

Smartly

ScaleupMediaAIForeign

Smartly powers better ai advertising. Fuel better cross platform advertising performance with ai marketing tool, Smartly. Launch, manage, and update campaigns