This is a translation by Emeritus Professor Alun O. Morris from his book Linear Algebra - An Introduction, which first appeared in 1978 and was published by Van Nostrand Reinhold. A second edition appeared in 1982 and over the years there have been numerous reprints. The book was also translated into Greek and Turkish. Although the book has been out of print in English for some years now, it is clear that it is still being used at a number of universities and so it was decided to translate it into Welsh. The translation was originally located in Aberystwyth University's online research repository.  https://cadair.aber.ac.uk/dspace/?locale-attribute=cy