26 October 2021

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Stanley-5 spud

Mosman Oil and Gas Limited (AIM: MSMN) the oil exploration, development and production company, announces that the Stanley-5 well in Polk County, East Texas has now been spudded.

Stanley-5 is a development well targeting the Yegua formation, at approximately 5,000 feet.

Mosman's interest in this well is c36.5% and will fund its share of the USD 350,000 drilling costs from existing cash resources.

Qualified Person's Statement                                                                    

The information contained in this announcement has been reviewed and approved by Andy Carroll, Technical Director for Mosman, who has over 35 years of relevant experience in the oil industry. Mr. Carroll is a member of the Society of Petroleum Engineers.

Market Abuse Regulation (MAR) Disclosure

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 ('MAR') which has been incorporated into UK law by the European Union (Withdrawal) Act 2018. Upon the publication of this announcement via Regulatory Information Service ('RIS'), this inside is now considered to be in the public domain.

Enquiries:

Updates on the Company's activities are regularly posted on its website:

www.mosmanoilandgas.com