Siti Aisyah Alias is a Malaysian mycologist and Deputy Executive Director of the Institute of Ocean and Earth Sciences, Universiti Malaya. Since 2001, she has been the Deputy Director of the National Antarctic Research Centre (NARC) and the Malaysian Antarctic Research Programme (MARP). In January 2023, she became the Director of the National Antarctic Research Centre (NARC) Malaysia.

Her scientific research fields include fungal biodiversity of marine fungi and polar soil fungi, antimicrobial activity and cold-adapted enzymes, and biochemistry of polar microbes. She has described more than twenty new marine fungi to science and published more than 125 peer-reviewed articles. She is co-author and co-editor of 28 books, including two books, namely Checklist of Fungi of Malaysia and Marine Fungi from Mangroves of Malaysia. Under the Higher Institute of Centre of Excellence (HICoE), she is leading a project on Latitudinal Differences in Response and Adaptation of Microbes to Atmospheric Changes.

She has significant field experience in the tropics, the Antarctic, and the Arctic, participating in eight polar research expeditions as a result of her strong international networking and collaboration and these include Australian Antarctic (AAD), Instituto Antarctico Chileno (INACH), Instituto Antarctico Equatoriano (INAE), Korean Polar Research Institute (KOPRI), Polish Polar Department and British Antarctic Survey.  She has helped the Malaysian Antarctica Program to develop through her international collaboration. She is also active in outreach activities to promote STEM and polar sciences. She participated in Malaysian Antarctic Research Program (MARP)’s outreach programmes to promote awareness of Antarctica among undergraduate students and secondary school pupils in Malaysia. This outreach activity is called Malaysia’s Journey to the Ice: Women in Antarctica, part of the MOSTI Social Innovation (MSI) grant (2015 – 2017). She has assisted in the development of Malaysia’s Antarctic policies and practices following the country’s accession to the Antarctic Treaty under a grant from the Ministry of Higher Education for the development of Science and Policy in Antarctica (2014- 2017).  Currently, she assists in developing Malaysia's Antarctic Bill.

In recognition of her various achievements as a lecturer and researcher, Dr. Siti was awarded Saintis Muda Negara in 2000, CTI-CFF Women Leaders Forum Program and the only Malaysian represented in Wikipedia as recognition for women and their work in Antarctic Research (2016) and MOHE Women Across the World: “Saintis Wanita Terkemuka Dunia Dari 30 Negara Dalam Bidang Sains Antartika”, MOHE, 2018. In 2022, she was featured among the '100 Women Scientists in Global Polar Research'.

She sits on various national and international panels such as the MOSTI Science Fund evaluation panel, Asia Forum of Polar Sciences (AFOPs) Panel and Academy of Science Malaysia (ASM) Taskforce Member on Antarctica, Selection Advisory Committee for Australian Research Council (ARC), Subject Matter Expert (SME) for Malaysia Education Blueprint, Academy Sciences of Malaysia and Board Member and Jury in Universal Scientific (USERN) in the field of Biological Sciences since 2019. She is also a Fellow of the Academy of Sciences Malaysia.