--- title: "Marketing Agencies in Connecticut: 401 Listed (2026)" description: "Ken's database lists 401 marketing agencies headquartered in Connecticut (Oct 17, 2026). See the size breakdown, the largest firms and the filter." path: /data/marketing-agencies-in-connecticut family: data updated: 2026-10-17 data_as_of: 2026-10-17 html: /data/marketing-agencies-in-connecticut sources: - "https://app.ken.so" - "/pricing" facts: company_count: "401" state: "Connecticut" industry_filter: "\"Advertising Services\" and \"Marketing Services\"" largest_size_band: "1-10 employees (82%)" data_as_of: "Oct 17, 2026" source: "Ken Search, POST /v1/search/companies" --- # Marketing Agencies in Connecticut Ken's database lists 401 marketing agencies headquartered in Connecticut as of Oct 17, 2026. The largest group, 82%, has 1-10 employees. ## Ken Search Results ### Ken Search Query: Industry: "Advertising Services" and "Marketing Services"; HQ state: Connecticut; HQ country: United States; Employees on record: 1 or more | Field | Value | | --- | --- | | Companies | 401 | | 1-10 employees | 327 (82%) | | 11-50 employees | 60 (15%) | | 51-200 employees | 6 (1%) | Ken's database, Oct 17, 2026. Headquarters counts, refreshed weekly. Action: [Search these companies free in Ken](/waitlist) (cost: Free to search, 1 credit ($0.02) per valid email) ## How Many Marketing Agencies Are in Connecticut? **In short:** 401 marketing agencies in Ken's database have their headquarters in Connecticut (Oct 17, 2026). Ken's database lists 401 marketing agencies with headquarters in Connecticut. The largest group, 82%, has 1-10 employees. A company with only a branch office in Connecticut is not counted. **Marketing Agencies in Connecticut by employee range, Oct 17, 2026** | Employees | Companies | Share | | --- | --- | --- | | 1-10 | 327 | 82% | | 11-50 | 60 | 15% | | 51-200 | 6 | 1% | | 201-500 | 4 | 1% | | 501-1,000 | 1 | <1% | | Not listed | 3 | 1% | | Total | 401 | 100% | Employee range as listed on each company profile, for the companies in the count. Not listed means the profile shows no size. ## Largest Marketing Agencies in Connecticut **In short:** By employee count in Ken's database, the largest is Octagon in Stamford with 1,001-5,000 employees. **Largest marketing agencies headquartered in Connecticut by employee count, Oct 17, 2026** | Company | City | Employees | | --- | --- | --- | | Octagon | Stamford | 1,001-5,000 | | MMA (Marketing Management Analytics) | Norwalk | 501-1,000 | | Affinion Group | Stamford | 501-1,000 | | On Line Marketing | Trumbull | 51-200 | | Treehouse Marketing | Seymour | 51-200 | Company-level data from Ken's database, ranked by employee count. This table reads each company's state from its address, so it can include large companies the count above misses because their record stores the state with a ZIP code. Public bodies, schools, job boards and companies with 50 employees or fewer are left out. ## How We Counted **In short:** We counted marketing agencies in Ken's database with headquarters in Connecticut on Oct 17, 2026. - Filter: Companies in Advertising Services or Marketing Services, with headquarters in Connecticut, United States, and at least one employee on record. - Headquarters only. Companies with just an office in Connecticut are not counted. - These are companies in Ken's database (250M people and 24M companies), not every company that exists. - Some records store the state with a ZIP code, and the state filter misses those, so read the count as a floor. The largest-companies table reads the state from each record's address, so it includes them. - Counts as of Oct 17, 2026. We check them weekly, and the dates move only when a count or a listed company changes. - Pages publish only at 50 companies or more. Ken is our product, and these counts come from its company database. The request body for POST /v1/search/companies ```json {"industries":["Advertising Services","Marketing Services"],"countries":["US"],"states":["Connecticut"],"employeesCount":{"min":1},"pageSize":0} ``` ## FAQ ### How many marketing agencies are in Connecticut? Ken's database lists 401 marketing agencies headquartered in Connecticut as of Oct 17, 2026. ### Which marketing agencies in Connecticut have the most employees? In Ken's database, Octagon, MMA (Marketing Management Analytics) and Affinion Group have the most employees of the marketing agencies headquartered in Connecticut. ### Can I get a list of marketing agencies in Connecticut? Yes. Run the filter on this page in Ken Search. Searching is free, and a valid email costs 1 credit ($0.02). ### How often is this count updated? We check it weekly. The dates on this page move only when a count or a listed company changes, so an older date means nothing moved since. ### Why does this count differ from other sources? Sources count differently: headquarters or any office, industry labels or government codes, and how many companies they track. This page counts headquarters in Ken's database with the filter shown above. ## Do this in Ken ### Search these companies in Ken Open Ken Search with the same filter to see all 401 companies, narrow them by size or city, and find a valid email for the people you want to reach. 1. Set these filters: Industry: "Advertising Services" and "Marketing Services"; HQ state: Connecticut; HQ country: United States; Employees on record: 1 or more. 2. Narrow by employee range or city. 3. Find valid emails and add the companies to a campaign. - Link: [Search these companies in Ken](/waitlist) - API: `POST /v1/search/companies` - MCP tool: `search_search_companies` - Cost: Free to search, 1 credit ($0.02) per valid email ## Related - [B2B company counts by industry and state](/data) - [Marketing Agencies in New York](/data/marketing-agencies-in-new-york) - [Marketing Agencies in Utah](/data/marketing-agencies-in-utah) - [Marketing Agencies in New Jersey](/data/marketing-agencies-in-new-jersey) - [Marketing Agencies in Florida](/data/marketing-agencies-in-florida) - [Marketing Agencies in Ohio](/data/marketing-agencies-in-ohio) ## Sources | Source | URL | Checked | | --- | --- | --- | | Ken's company database, queried through Ken Search (POST /v1/search/companies) | https://app.ken.so | 2026-10-17 | | Ken pricing (credit cost per valid email) | /pricing | 2026-10-17 | ## Changelog - 2026-10-17: Page published with counts from Ken's database.