The aim of this thesis is to systematically review the literature related to the estimation of air ticket price elasticity and conduct a meta-analysis to examine the determinants to which the variation of its estimates is attributed. A total number of 258 estimates of air ticket price elasticity of demand were collected from 44 studies conducted internationally from 1974 to 2020. Meta-regression models were developed, including fixed-effects and random-effects models. The independent variables of the meta-regression are related to various geo-economic (coverage area, flight distance, passenger category, etc.) and study-descriptive characteristics (data time period, publication type, etc.) of each individual sample estimate of the reviewed studies. The results of this thesis provide useful insights into the variation of the estimated ticket price elasticities of air-travel demand and can be of great interest to several aviation stakeholders such as airports, airlines and civil aviation authorities.