Commercially available ammonia gas detectors are expensive and become cost-prohibitive for applications requiring the use of a multitude of these sensors. Additively manufactured flexible electronic sensors can be utilized to adapt to varying environments, with added benefits of low production costs and minimal materials wastage. In terms of a suitable material for Ammonia detection, carbon nanotube (CNTs) have demonstrated the capability of reacting to multiple chemicals with high specificity depending on the formulation of the CNTs. This work seeks to demonstrate the viability of utilizing additive manufacturing technique to deposit metallic CNTs on a silver electrode array as a means to detect ammonia gas. The sensor is fully ink-jet fabricated by first printing a silver reference electrode array and then printing CNTs over the array. Our work also involves optimizing a CNT ink that will continuously jet and react well with ammonia gas, leading to a viable low-cost development of Ammonia sensors that could be widely deployed.