Mairi Aitken graduated in drawing and painting from The Glasgow School of Art. After gaining a teaching certificate from Jordanhill College of Education she went on to teach in a number of schools in both Scotland and England.

Mairi Aitken is a past president of the Glasgow Society of Women Artists and exhibits regularly with them . She is also a member of the Paisley Art Institute where she won the Arnold Clark Prize (1997), the John Green Purchase Prize (2000), the William Grant & Sons Charitable Trust Award (2001) and the Institute's Prize for the 'small work' chosen by the public (2001).

Other awards won by Mairi Aitken include the Anne Stevenson Memorial Award (2004), the Strathkelvin Council Purchase Prize (1996), and the E Dunbartonshire Council Purchase Prize (1997 & 1998). Her work has been acquired by schools, councils, the Royal Bank of Scotland and is in private collections in the UK, Europe and the USA.

Mairi Aitken's work is mostly figurative, based largely on scenes recorded whilst holidaying abroad, and with particular emphasis on strong light, shade and people going about their everyday lives. She works mainly in acrylics.