Mark Hannigan (Realty 123 Inc.) Real Estate Broker/Owner



Mark Hannigan
location_on Hauppauge, NY — Realty 123 Inc.
Get to Know Mark Hannigan

Mark Hannigan Licensed Real estate Broker, CBR, SRES, Your real estate marketing specialist.

Mark Hannigan is a Licensed Real Estate Broker who specializes in consulting motivated buyers and sellers in order to help them achieve their real estate goals.  Before starting his real estate career, Mark was highly decorated New York City Police Officer.

Mark has achieved numerous awards and recognitions thru out both his careers.  He is a qualified Previews agent specializing in Waterfront and Luxury Homes. He holds a NYS brokers licensed as well as a Certified Buyer Representative and Senior Real Estate Specialists designation.  Mark provides service, guidance and professionalism.

In between careers Mark took off 5 years to help his wife Cathy raise their 4 children.  He says "I have a new respect for the work it takes to run a household."  Family, work and charity events are enough to keep anyone busy, and Mark loves them all.


Helping Buyers and Sellers with all their Real estate needs. I have several web-sites that will help you in your search or sale of a residential property. Waterfront Homes, Residential Homes:,,

The internet is a great place to search for or to market a home. I provide both buyers and sellers the key tools to be successful in their quest. As much as the internet is a powerful tool, there is nothing better than sitting down with Mark and his team to discuss your plans and real estate desires.

Understanding Representation: Most agents just represent the seller, I represent sellers when I list their home, I also represent buyers when purchasing a home. You can and should be represented in your real estate transaction, ask me how.


We offer Long Island homeowners the ability to save thousands of commission dollars when selling their homes.


Waterfront and Luxury Residential Homes services in: Hauppauge, Babylon, Bay Shore, Brightwaters, Bayport, Blue Point, Islip, Islip Terrace, East Islip, Great River, Oakdale, Sayville and West Islip