RYANAIR covered a number of routes from Shannon, which was described as a "serious blow" in the region.
Low cost airlines will no longer fly to Bristol, East Midlands Airport and the sunny resort of Ibiza from January.
Senator Maria Byrne said she was disappointing, especially following the recent postponement of 13 services per week in Shannon due to the grounding of Boeing 737 Max aircraft earlier this year.
"This is another significant obstacle to economic growth in the Midwest region," she added, "more needs to be done to support Shannon because airports play such a significant role in economic development and job creation."
"2019 was a very difficult year for Shannon Airport, but I call for more support for our local international airport, especially in connection with preparations for the Ryder Cup at Adare Manor in 2026.
"It is very important that we do not lose the significant economic benefits that such a renowned event in this region will bring.
"Work on the Trojans continued in the further development of the region, but development cannot continue without the flourishing Shannon airport, which offers a wide range of services and routes to and from our magnificent part of Ireland.
"At a time when great work was done to promote tourism in the west of Ireland, such as the rapid development of the Wild Atlantic, it is very disappointing today that the loss of these three services was today," Byrne said.
Meanwhile, Mary Considine, acting Chief Executive Officer of Shannon Airport, added: "We are disappointed with Ryanair's decision to limit Shannon's services to Bristol, East Midlands and Ibiza since January 2020. In light of the slowdown in the global economy and Brexit uncertainty, this is a particularly difficult period for global aviation. Only last week we witnessed the closure and suspension of flights by three European airlines. "
However, she added: "Ryanair is a valued partner for airlines and we understand the turbulent global economic climate facing the aviation industry. Ryanair will continue to operate 15 routes and carry 775,000 passengers from Shannon in 2020, and we are actively working with all our airline partners to explore the possibilities of attracting new Shannon services. "