This article is from the comp.sys.acorn FAQ, by Paul Vigay with numerous contributions by others.
Currently, no. Acorn did have, in the early days of the experimental ARM work, an in house compiler. However this compiler was sufficiently unstable and buggy to be un-releasable as a commercial product and was only used because in house support was available immediately to the users of the compiler. When Olivetti invested in Acorn this technology went to them so that Acorn no longer have even an in house Modula 2 compiler.
However some companies have stated intentions to produce Modula 2 compilers for the Arc. Whether these intentions become reality has yet to be seen.