Referring to God as Jehovah is a known practice by Jehovah's Witnesses as written by Raymond Franz in In Search of Christian Freedom in 1991:
The fact remains that today no religious group of any size uses the name "Jehovah" with such intense frequency as does that of Jehovah's Witnesses. That name predominates throughout their literature. Among Jehovah's Witnesses it has become almost strange to speak of "God" without prefacing the term by saying "Jehovah God", while the term "Lord" is quite rare in their expressions. They read "Lord" in the Bible but hardly ever use it in their own speech extemporaneously. It is almost a liturgical form for them in most prayers to initially address these to "Jehovah" or "Jehovah God".
However, the above was written after his expulsion, and thus may not carry any significant doctrinal weight.
Are there other denominations or religions that understand God's personal name as the form "Jehovah"?