Every field has its authorities (Edward Wittins in Physics, Harold Bloom in Literature, Stanley Hauerwas in Theology to mention but a few). Same is true of the digital marketing field as well. There are a set of people who based on their exhibited expertise, depth of understanding and professional acumen have earned the tag \”authority\” in the field of digital marketing.
While there are several digital marketing \”experts\”, very few are qualified to be called \”authority\”. Below is a list of our favourite notable digital marketing authorities alive.

Classification By Subject Areas
Rather than do a generic list, what I have done is to group the experts into four distinct subject areas in digital marketing: SEO, PPC, CRO/Analytics, General Strategy

Search Engine Optimization

Rand Fishkin

Rand is the co-founder of Moz and served as the CEO of the company until last month. Moz is one of the marketing world\’s fastest growing software companies. Rand Fishkin\’s knowledge of SEO is overwhelming. More important however is his willingness to share all that he knows–for free. His company blog is arguably the richest source of up to date SEO resources. What surprises me the most about Rand is that he never lowers the standard of his write ups as I am yet to see a mediocre or even an average stuff from him.
Rand Fishkin co-authored the Art of SEO from O\’Reilly Media, co-founded Inbound.org, and was named on PSBJ\’s 40 Under 40 List and BusinessWeek\’s 30 Best Tech Entrepreneurs Under 30.

Will Critchlow

Will is a nerd. An artistic nerd with a mathematics degree from the University of Cambridge (St. John’s College) including a graduate thesis on auction theory.
Will founded Distilled with Duncan in 2005. Since then, he has consulted with some of the world’s largest organizations and most famous websites, spoken at most major industry events and regularly appeared in local and national press.
His knowledge of search marketing is encyclopedic.

Neil Patel

Neil is a generous soul. I mean, how do you explain someone who spends tens of thousands dollars to produce top-notch digital marketing tools and guides only to give the resources away FREE? I have learned more from Neil than any other person in the area of inbound marketing.
Patel launched his first online venture, a job board named Advice Monkey, while in high school. The inability of the marketing companies he hired for the project to deliver meaningful result propelled him to learn how to drive traffic to his site, thus launching his career in online marketing. By 2009, Patel had become so good in marketing and search engine optimization that his expertise was engaged by 30 of the top 100 Technorati blogs and was named one of the top influencers on the web by The Wall Street Journal

Paid Search

Larry Kim

When it comes to paid search, Larry is head above the rest. He is simply the best mind in paid search today.
Larry\’s background has been in software engineering, software product management, and Internet Marketing (particularly PPC, SEO and Social Media Marketing), for several widely-used software productivity tools over 10 years.
In recognition of his pre-eminence in paid search, Larry was voted as the most influential PPC expert in 2013 according to the PPC Hero Blog and won a spot in the ClickZ Digital Marketing Hall of Fame and Small Business Influencer Award in 2013. In 2015 Larry also won Search Marketer of the Year Awards from the US Search Awards and Search Engine Land.
Larry is the founder and Chief Technical Officer of Wordstream, a leading provider of AdWords, Facebook and keyword tools used by over a million marketers worldwide.

Marty Weintraub

Marty is the least known person to me on the list. However, almost all the people I consulted before writing this post agree that he is one of the leading authorities in Paid Search
Marty is the Founder & Evangelist of aimClear® an integrated social, search, display and PR online marketing agency. Client credits include Intel, Siemens, Tektronix, United Health Group, MarthaStewart.com, The Washington Post, Ning, SecondLife & other iconic global brands.
He has written extensively for respected Internet marketing publications including SearchEngineWatch, SearchEngineLand, SearchEngineRoundTable and been quoted in others, from AdAge to MediaPost

Pat East

Pat is the Founder of PPC Hero, the industry’s leading and most highly trafficked paid search marketing blog. PPC Hero delivers search marketing thought leadership and expertise from the PPC experts at Hanapin Marketing.
A university professor, Pat has probably impacted more PPC practitioners than any other person. He is also the Founder and CEO of Hanapin Marketing, a premier digital marketing agency that specializes in paid search marketing.

Analytics/CRO

Avinash Kaushik

The major advantage of digital marketing over traditional marketing is the former\’s data-driven nature. Every element of digital marketing can be tracked, measured and optimized. This goes to show the importance of data management and analytics skills to a modern marketer. Avinash has probably contributed to this field than any other person.
Avinash is the Digital Marketing Evangelist for Google (Data-driven decision making uncomplexified); The Co-Founder and Chief Education Officer for Market Motive; The author of two bestselling books: Web Analytics 2.0, Day. He has won several awards, including:
– Statistical Advocate of the Year from the American Statistical Association, 2009
– Rising Star award from the Direct Marketing Educational Foundation, 2010
– Most Influential Industry Contributor from the Web Analytics Association, 2011
– Featured in the \”Pioneers of Digital\” book, with a bunch of amazing people I admire! 2012

Annie Cushing

If Avinash is the king of analytics, Annie is the undisputed queen.
Annie loves all things data visualization and analytics so much that someone once dubbed her Annielytics. And it kind of stuck.
She is good. She is extremely brilliant and uncommonly selfless. Yes, selfless. She created a monster marketing tools resource for her fellow marketers (hundreds of tools) and a kissing cousin audit checklist and gave them away for free!

Oli Gardner

It was so difficult to decide on which category to put Oli. He is an all-rounder. His Noob Guide To Internet Marketing is a landmark in the history of content creation. I eventually decided to put him in the CRO category because his expertise in this area is unassailable.
He is a Co-Founder & Director of Marketing at Unbounce.com

Social Media Marketing

It is hard to agree on which one has the highest number of quackery between SEO and social media marketing. Because of the zero barriers to entry in these two fields, anybody can claim to be SEO expert the same way anybody with a Facebook account can call himself social media guru.
Luckily, in this ocean of ineptitude, there are a few people with the highest level of professionalism, knowledge and adroitness.

Brian Solis

Brian Solis is principal at Altimeter Group, a research firm focused on disruptive technology. A digital analyst, anthropologist, and futurist, Solis has studied and influenced the effects of emerging technology on business, marketing, and culture. Solis is also globally recognized as one of the most prominent thought leaders and published authors in new media. His new book, What\’s the Future of Business (WTF), explores the landscape of connected consumerism and how business and customer relationships unfold and flourish in four distinct moments of truth. His previous book, The End of Business as Usual, explores the emergence of Generation-C, a new generation of customers and employees and how businesses must adapt to reach them. Prior to End of Business, Solis released Engage, which is regarded as the industry reference guide for businesses to market, sell and service in the social web.
His website is a treasure trove of social media marketing wealth

Michael Stelzner

Michael Stelzner is one of the most recognizable names in the world of social media marketing. Michael founded Social Media Examiner in 2009 with the goal of providing free how-to information about social media.
Content marketing is the buzzword in digital marketing now but way back in 2011, Stelzner wrote Launch: How to Quickly Propel Your Business Beyond the Competition (Wiley) in which he introduces the concept of “content as fuel” for businesses. As Stelzner describes in an interview with Bryan Elliot of Entrepreneur, “Primary fuel is regularly produced free content that meets the needs of readers. This type of content includes how-to articles, case studies, and reviews.”

Jeremiah Owyang

Jeremiah states that his career mission is to help corporations connect with customers using web technologies. He does this by researching the way disruptive technologies are changing the customer relationship, by speaking at many conferences and events, and by serving as a frequent source for the media.
Since 2006, his blog has been the place where he shares insights from his research and what it means for a business of the future.
Jeremiah lives at the edge of technology but maps it back to what it means for businesses. This has led him to early thinking in the realms of customer experience, social business, interactive marketing, and now the collaborative economy.
In addition to his blog, Jeremiah and his team have published numerous research reports focused on social business and the collaborative economy. They focus on topics like how products, services, and markets have changed with the collaborative economy; how businesses manage complex, scaled social media programs; and the career path of the new social strategist. The reports are open research and can be accessed by anyone

Strategy

Dave Chaffey

Without a well-articulated strategy, marketing effectiveness is compromised. A well-developed strategy simplifies your everyday marketing job as it makes the implementation of different initiatives straight-forward.
Dave is the go-to authority on anything digital marketing strategy. Don\’t take my word for it, in 2004 he was recognized by the Chartered Institute of Marketing as one of 50 marketing ‘gurus’ worldwide who has helped shape the future of marketing. His RACE Digital Marketing Planning model remains the best digital marketing planning model out there
Dave is the author of 5 bestselling books on digital marketing including Emarketing Excellence and Digital Marketing: Strategy, Implementation, and Practice