Elliott embarked for Australia on the RMS "Orontes" on 15 May 1919, sharing a cabin with an old friend, Brigadier General Gordon Bennett. They arrived back in Melbourne on 28 June, and his AIF appointment was terminated the following day. He contested the federal election as a candidate for the Nationalist Party of Australia on 13 December 1919. He achieved the greatest popular vote of any Victorian candidate for the Senate. Moreover, he repeated this success at the 1925 election. Although not naturally suited to life in the federal parliament, he made significant contributions, and was outspoken in his efforts to assist returned servicemen, particularly those with whom he had served. This outspokenness often took the form of arguing in the Senate in relation to the new legislation being brought before it, when such legislation involved the defence forces. At other times, he would personally champion the cause of those men who had been in his battalion.