Exhibit 99.1

PRESS RELEASE FOR IMMEDIATE ISSUE

MDC PARTNERS INC. REPORTS RESULTS FOR THE
THREE AND NINE MONTHS ENDED SEPTEMBER 30, 2017

THIRD QUARTER HIGHLIGHTS:

YEAR-TO-DATE HIGHLIGHTS: 

New York, NY, October 30, 2017 (NASDAQ: MDCA) – MDC Partners Inc. (“MDC Partners” or the “Company”) today announced financial results for the three and nine months ended September 30, 2017.

Scott Kauffman, Chairman and Chief Executive Officer of MDC Partners, said, “Our business delivered another strong quarter, highlighted by industry-leading organic revenue growth of 7.8%, nearly $26 million of net new business, and increases in both Adjusted EBITDA and Adjusted EBITDA margin. We’re particularly pleased with our ongoing success securing high profile, global and integrated assignments for some of the world’s most iconic brands, demonstrating how our portfolio of world-class agencies continues to capitalize on the changing marketing and communications landscape. We’re very excited about the opportunity ahead of us.”

David Doft, Chief Financial Officer of MDC Partners, said, “It is shaping up to be the improved year we expected, which keeps us on track to achieve all of our full year financial targets. We remain committed to our additional goals of de-leveraging the company over time even while advancing our strategic capabilities, including the reduction of our deferred acquisition consideration and minority interest, as well as our leverage ratio. We continue to believe that an improved balance sheet in conjunction with expanding profits will result in attractive equity returns for shareholders.”

Third Quarter and Year-to-Date 2017 Financial Results

Revenue for the third quarter of 2017 was $375.8 million, an increase of 7.6%, compared to $349.3 million in the third quarter of 2016. The effect of foreign exchange was positive 0.8%, the impact of non-GAAP acquisitions (dispositions), net was negative 0.9%, and the resulting organic revenue growth was 7.8%. Organic revenue growth for the period was favorably impacted by 180 basis points from increased billable pass-through costs incurred on clients’ behalf from certain of our partner firms acting as principal.

Net income attributable to MDC Partners common shareholders in the third quarter of 2017 was $16.5 million compared to a loss of ($32.1) million in the third quarter of 2016. Diluted income per share attributable to MDC Partners common shareholders for the third quarter of 2017 was $0.24 compared to a loss of ($0.62) per share in the third quarter of 2016. Adjusted EBITDA for the third quarter of 2017 was $53.8 million, an increase of 16.4% compared to $46.3 million in the third quarter of 2016, with margins expanding by 110 basis points versus last year.

Revenue for the first nine months of 2017 was $1.11 billion, an increase of 11.6%, compared to $995.3 million in the first nine months of 2016. The effect of foreign exchange was negative 0.4%, the impact of non-GAAP acquisitions (dispositions), net was positive 3.7%, and the resulting organic revenue growth was 8.4%. Organic revenue growth for the period was favorably impacted by 200 basis points from increased billable pass-through costs incurred on clients’ behalf from certain of our partner firms acting as principal.

Net income attributable to MDC Partners common shareholders in the first nine months of 2017 was $14.8 million compared to a loss of ($54.9) million in the first nine months of 2016. Diluted income per share attributable to MDC Partners common shareholders for the first nine months of 2017 was $0.24 compared to a loss of ($1.08) per share in the first nine months of 2016. Adjusted EBITDA for the first nine months of 2017 was $136.6 million, an increase of 13.0% compared to $121.0 million in the first nine months of 2016, with margins expanding by 10 basis points versus last year.

Financial Outlook

Guidance for 2017 is maintained as follows:

Conference Call

Management will host a conference call on Monday, October 30, 2017, at 4:30 p.m. (ET) to discuss results. The conference call will be accessible by dialing 1-412-902-4266 or toll free 1-888-346-6216. An investor presentation has been posted on our website www.mdc-partners.com and may be referred to during the conference call.

A recording of the conference call will be available one hour after the call until 12:00 a.m. (ET), November 6, 2017, by dialing 1-412-317-0088 or toll free 1-877-344-7529 (passcode 10113763), or by visiting our website at www.mdc-partners.com.

About MDC Partners Inc.

MDC Partners is one of the fastest-growing and most influential marketing and communications networks in the world. Its 50+ advertising, public relations, branding, digital, social and event marketing agencies are responsible for some of the most memorable and engaging campaigns for the world’s most respected brands. As "The Place Where Great Talent Lives," MDC Partners is known for its unique partnership model, empowering the most entrepreneurial and innovative talent to drive competitive advantage and business growth for clients. By leveraging technology, data analytics, insights, and strategic consulting solutions, MDC Partners drives measurable results and optimizes return on marketing investment for over 1,700 clients worldwide. For more information about MDC Partners and its partner firms, visit our website at www.mdc-partners.com and follow us on Twitter at http://www.twitter.com/mdcpartners.

Non-GAAP Financial Measures

In addition to its reported results, MDC Partners has included in this earnings release certain financial results that the Securities and Exchange Commission defines as "non-GAAP financial measures." Management believes that such non-GAAP financial measures, when read in conjunction with the Company's reported results, can provide useful supplemental information for investors analyzing period to period comparisons of the Company's results. Such non-GAAP financial measures for the three and nine months ended September 30, 2017, include the following:

(1) Organic Revenue: “Organic revenue growth” and “organic revenue decline” refer to the positive or negative results, respectively, of subtracting both the foreign exchange and acquisition (disposition) components from total revenue growth. The acquisition (disposition) component is calculated by aggregating prior period revenue for any acquired businesses, less the prior period revenue of any businesses that were disposed of during the current period. The organic revenue growth (decline) component reflects the constant currency impact of (a) the change in revenue of the partner firms which the Company has held throughout each of the comparable periods presented, and (b) “non-GAAP acquisitions (dispositions), net”. Non-GAAP acquisitions (dispositions), net consists of (i) for acquisitions during the current year, the revenue effect from such acquisition as if the acquisition had been owned during the equivalent period in the prior year and (ii) for acquisitions during the previous year, the revenue effect from such acquisitions as if they had been owned during that entire year (or same period as the current reportable period), taking into account their respective pre-acquisition revenues for the applicable periods, and (iii) for dispositions, the revenue effect from such disposition as if they had been disposed of during the equivalent period in the prior year.

(2) Net New Business: Estimate of annualized revenue for new wins less annualized revenue for losses incurred in the period.

(3) Adjusted EBITDA: Adjusted EBITDA is a non-GAAP measure that represents operating profit plus depreciation and amortization, stock-based compensation, deferred acquisition consideration adjustments, distributions from non-consolidated affiliates, and other items. Prior to 2017, Adjusted EBITDA included an additional adjustment for acquisition deal costs. Beginning with 2017, on a prospective basis we no longer include the acquisition deal cost adjustment but we continue to disclose this metric on Schedule 9 for your reference.

Included in this earnings release are tables reconciling MDC Partners’ reported results to arrive at certain of these non-GAAP financial measures. We are unable to reconcile our projected 2017 organic revenue growth to the corresponding GAAP measure because we are unable to predict the 2017 impact of foreign exchange due to the unpredictability of future changes in foreign exchange rates and because we are unable to predict the occurrence or impact of any acquisitions, dispositions, or other potential changes. We are unable to reconcile our projected 2017 increase in Adjusted EBITDA margin to the corresponding GAAP measure because the amount and timing of many future charges that impact these measures (such as amortization of future acquired intangible assets, foreign exchange transaction gains or losses, impairment charges, provision or benefit for income taxes, and certain assumptions used in the calculation of deferred acquisition consideration) are variable, uncertain, or out of our control and therefore cannot be reasonably predicted without unreasonable effort, if at all. As a result, we are unable to provide reconciliations of these measures. In addition, we believe such reconciliations could imply a degree of precision that might be confusing or misleading to investors.

This press release contains forward-looking statements. The Company’s representatives may also make forward-looking statements orally from time to time. Statements in this press release that are not historical facts, including statements about the Company’s beliefs and expectations, earnings guidance, recent business and economic trends, potential acquisitions, and estimates of amounts for redeemable noncontrolling interests and deferred acquisition consideration, constitute forward-looking statements. These statements are based on current plans, estimates and projections, and are subject to change based on a number of factors, including those outlined in this section. Forward-looking statements speak only as of the date they are made, and the Company undertakes no obligation to update publicly any of them in light of new information or future events, if any.

Forward-looking statements involve inherent risks and uncertainties. A number of important factors could cause actual results to differ materially from those contained in any forward-looking statements. Such risk factors include, but are not limited to, the following:

The Company’s business strategy includes ongoing efforts to engage in acquisitions of ownership interests in entities in the marketing communications services industry. The Company intends to finance these acquisitions by using available cash from operations, from borrowings under its credit facility and through incurrence of bridge or other debt financing, any of which may increase the Company’s leverage ratios, or by issuing equity, which may have a dilutive impact on existing shareholders proportionate ownership. At any given time, the Company may be engaged in a number of discussions that may result in one or more acquisitions. These opportunities require confidentiality and may involve negotiations that require quick responses by the Company. Although there is uncertainty that any of these discussions will result in definitive agreements or the completion of any transactions, the announcement of any such transaction may lead to increased volatility in the trading price of the Company’s securities.

Investors should carefully consider these risk factors and the additional risk factors outlined in more detail in the Annual Report on Form 10-K under the caption “Risk Factors” and in the Company’s other SEC filings.

SCHEDULE 1

MDC PARTNERS INC.

UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS

(US$ in 000s, except share and per share amounts)

SCHEDULE 2

MDC PARTNERS INC.

UNAUDITED ORGANIC REVENUE GROWTH RECONCILIATION

(US$ in 000s, except percentages)

Note: Actuals may not foot due to rounding.

SCHEDULE 3

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

For the Three Months Ended September 30, 2017

SCHEDULE 4

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

For the Three Months Ended September 30, 2016

SCHEDULE 5

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

For the Nine Months Ended September 30, 2017

SCHEDULE 6

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

For the Nine Months Ended September 30, 2016