65 ILCS 5/3.1-25-20
A village incorporated under this Code shall nominate and elect candidates for president and trustees in nonpartisan primary and general elections as provided in Sections 3.1-25-20 through 3.1-25-55 until the electors of the village vote to require the partisan election of the president and trustees at a referendum in the manner provided in Section 3.1-25-65 after January 1, 1992. The provisions of Sections 3.1-25-20 through 3.1-25-55 shall apply to all villages incorporated under this Code that have operated under those Sections without the adoption of those provisions by the referendum provided in Section 3.1-25-60 as well as those villages that have adopted those provisions by the referendum provided in Section 3.1-25-60 until the electors of those villages vote to require the partisan election of the president and trustees in the manner provided in Section 3.1-25-65. Villages that have nominated and elected candidates for president and trustees in partisan elections prior to January 1, 1992, may continue to hold partisan elections without conducting a referendum in the manner provided in Section 3.1-25-65. All candidates for nomination to be voted for at all general municipal elections at which a president or trustees, or both, are to be elected under this Article shall be nominated from the village at large by a primary election.
Notwithstanding any other provision of law, no primary shall be held in any village when the nomination for every office to be voted upon by the electors of the village is uncontested. If the nomination of candidates is uncontested as to one or more, but not all, of the offices to be voted upon by the electors of the village, then a primary must be held in the village, provided that the primary ballot shall not include those offices in the village for which the nomination is uncontested. For the purposes of this Section, an office is uncontested when not more than the number of persons to be nominated to the office have timely filed valid nominating papers seeking nomination for election to that office.
Notwithstanding the preceding paragraph, when a person (i) who has not timely filed valid nomination papers and (ii) who intends to become a write-in candidate for nomination for any office for which nomination is uncontested files a written statement or notice of that intent with the proper election official with whom the nomination papers for that office are filed, a primary ballot must be prepared and a primary must be held for the office. The statement or notice must be filed on or before the 61st day before the consolidated primary election. The statement must contain (i) the name and address of the person intending to become a write-in candidate, (ii) a statement that the person intends to become a write-in candidate, and (iii) the office the person is seeking as a write-in candidate. An election authority has no duty to conduct a primary election or prepare a primary ballot unless a statement meeting the requirements of this paragraph is filed in a timely manner.
Only the names of those persons nominated in the manner prescribed in Sections 3.1-25-20 through 3.1-25-65 shall be placed on the ballot at the general municipal election. The village clerk shall certify the offices to be filled and the candidates for those offices to the proper election authority as provided in the general election law. A primary for those offices, if required, shall be held in accordance with the general election law.
65 ILCS 5/3.1-25-20