Employee Stock Purchase Plan	6 Months Ended
Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Employee Stock Purchase Plan	13. Employee Stock Purchase Plan 2019 ESPP The Mesa Air Group, Inc. 2019 Employee Stock Purchase Plan ("2019 ESPP”) is a nonqualified plan that provides eligible employees of Mesa Air Group, Inc. with an opportunity to purchase Mesa Air Group, Inc. ordinary shares through payroll deductions. Under the 2019 ESPP, eligible employees may elect to contribute 1% to 15% of their eligible compensation during each semi-annual offering period to purchase Mesa Air Group, Inc. ordinary shares at a 10% discount. A maximum of 500,000 Mesa Air Group, Inc. ordinary shares may be issued under the 2019 ESPP. As of March 31, 2024, eligible employees purchased and we issued an aggregate of 499,962 Mesa Air Group, Inc. ordinary shares under the 2019 ESPP, 55,372 of which were purchased and issued during the three and six months ended March 31, 2024. During the three months ended March 31, 2024, the maximum amount of shares was reached and the 2019 ESPP was discontinued.

Employee Stock Purchase Plan

6 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

13.

Employee Stock Purchase Plan

2019 ESPP

The Mesa Air Group, Inc. 2019 Employee Stock Purchase Plan ("2019 ESPP”) is a nonqualified plan that provides eligible employees of Mesa Air Group, Inc. with an opportunity to purchase Mesa Air Group, Inc. ordinary shares through payroll deductions. Under the 2019 ESPP, eligible employees may elect to contribute 1% to 15% of their eligible compensation during each semi-annual offering period to purchase Mesa Air Group, Inc. ordinary shares at a 10% discount.

A maximum of 500,000 Mesa Air Group, Inc. ordinary shares may be issued under the 2019 ESPP. As of March 31, 2024, eligible employees purchased and we issued an aggregate of 499,962 Mesa Air Group, Inc. ordinary shares under the 2019 ESPP, 55,372 of which were purchased and issued during the three and six months ended March 31, 2024. During the three months ended March 31, 2024, the maximum amount of shares was reached and the 2019 ESPP was discontinued.