Yes, it is.
Both Low German and English didn't suffer High German consonant shift, besides the two languages are from North sea Germanic branch, so somehow they're a bit related to. Low German is the modern descendant of Old Saxon the language spoken by ancient Germanic tribe, Saxons but those Saxons stayed on their original fatherland that it's nowadays northern Germany and northeast of the Netherlands instead of migrating to England with Angles, other Saxons, Jutes and Frisians, where there with all the mix of their dialects it formed Anglo- Saxon language, the earliest version of English spoken nowadays.
Certainly it's very possible that it existed a great degree of intelligibility between Old English and Old Saxon, but nowadays both languages are not intelligible, because English centuries back was very influenced by Old Norse and Norman French, and then English adopted foreign vocabulary from many different languages on later periods.
Low German on the contrary was strongly influenced by standard German on recent eras in terms of vocabulary, orthography and grammar structures, losing some of their original characteristics for this reason, nowadays Low German it's more considered a German dialect more than an independent language itself, although it is. Low German dialects spoken in The Netherlands have received more Dutch influence in terms of vocabulary, orthography and grammar structures, in The Netherlands Low German it's known as Low Saxon.