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Sideline Group

Q: When was Sideline Group last fund created?

Sideline Group last fund was created/launched in 2026-04-20.

General contacts

Investor type

PE / VC

Founded

2021

AUM

$155 M

Location

New York City, New York, United States

Investment Ticket

$10-50 m

Investment Stage

Series B Seed Pre-seed Late Stage (Series C+)

Region of investment

North America

Investor profile last updated: 17 September, 2026

Profile

Sideline Group is a venture capital firm based in New York City, founded by Greg Mazlin, a former private equity investor at Silver Lake and partner at Tiger Global. The firm focuses on investing in sectors that intersect with consumer, sports, and media & entertainment, primarily targeting culture-setting brands and experiences. Sideline Group collaborates with growth-stage businesses supporting healthier, active lifestyles through events and experiences. The team comprises professionals with deep expertise in these areas, offering unique insights and value to their portfolio companies.

Sideline Group invests in the Offline Economy, backing brands and experiences that redefine consumer interaction with sports and media. Their fund structure allows them to write checks typically ranging from $10-50 million, targeting growth-stage investments with a geographic focus primarily in North America. Sideline Group Fund I, their debut fund, closed at $155 million, drawing capital from a wide array of institutional investors, including university endowments, funds of funds, and family offices.

Notable investments from Sideline Group include Bandit Running, a community-driven performance running brand; Urban Golf Performance, focusing on premium golf training; MARI, a company known for organizing global events like the Miami Open; and Milky Way Park, a platform for adventure sports. These investments reflect Sideline Group’s commitment to supporting innovative companies within their thematic focus areas.

Industry

Sports/SportsTech HoReCa/Hospitality Retail Media and Entertainment Marketing and Advertising Consumer Services (B2C) Consumer Products Technology

Sideline Group Funds

Name	Type	Industry	Stage	Region	Size	AUM	Launch date
Sideline Group Fund I	Venture Capital (VC)	Consumer Products Consumer Services (B2C) Marketing and Advertising Media and Entertainment Sports/SportsTech Technology	Pre-seed Seed Late Stage (Series C+)	North America	$5-10 m	$155 M	April 2026

Contacts

Name

Title

Social Networks

Greg Mazlin Founder

Founder

g•••@•••

Melissa Fulenwider Principal

Principal

m•••@•••

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Investment-team contacts for Sideline Group — including verified work emails and LinkedIn profiles — are available to Private Equity List subscribers.
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Contacts sourced from the firm's website and LinkedIn, re-verified on a rolling cycle. Spot a stale contact, or none at all? Report it — we re-run that firm within 48h and get back to you.

FAQs about Sideline Group

Is Sideline Group a venture capital or private equity firm?

Sideline Group is a venture capital and private equity firm. It backs companies at Series B, Seed, Pre-seed and Late Stage (Series C+), writing tickets of $10-50 m.

Where is Sideline Group located?

Sideline Group is located in New York City, New York, United States.

When was Sideline Group founded?

Sideline Group was founded in 2021.

What sectors and industries does Sideline Group invest in?

Sideline Group invests in companies and startups in Sports/SportsTech, HoReCa/Hospitality, Retail, Media and Entertainment, Marketing and Advertising, Consumer Services (B2C), Consumer Products, Technology.

What is Sideline Group geographical focus of investments?

Sideline Group invests in companies and startups in North America.

At what stages of companies and startups does Sideline Group typically invest in?

Sideline Group invests in companies and startups at Series B, Seed, Pre-seed, Late Stage (Series C+).

What is the usual amount of Sideline Group investment?

Sideline Group usually invests $10-50 m on average.

What is the amount of assets of under management (AUM) for Sideline Group?

Sideline Group has around $155m assets under management.

When was Sideline Group last fund created?

Sideline Group last fund was created/launched in 2026-04-20

What are the contacts of Sideline Group?

Sideline Group can be reached through its website sidelinegroup.co and its LinkedIn page. Its general enquiries address is [email protected]. Cold-mailing a general inbox rarely reaches a partner, so Private Equity List also lists the investment-team contacts for Sideline Group — names, roles, verified work emails and LinkedIn profiles — available on a Pro plan from $129/month (see pricing). Contacts are sourced from the firm's website and LinkedIn and re-verified on a rolling cycle. Spot a stale contact, or none at all? Report it — we re-run that firm within 48h and get back to you.

Can I access Sideline Group data via API or MCP?

Yes. Every field on this page — profile, funds, investment criteria, portfolio and investment-team contacts — is available programmatically through the Private Equity List REST API and MCP server, so AI assistants such as Claude and ChatGPT can query Sideline Group directly instead of scraping this page. One subscription covers both the web app and machine access — see API & MCP.

When was the Sideline Group profile last updated?

Private Equity List re-verifies investor profiles on a rolling cycle, pulling from the firm's own website and LinkedIn rather than a one-off import. This profile was last updated on 17 September, 2026. Something out of date here? Report it — we re-run that firm within 48h and get back to you.