Hilfikon is a village in the district of Bremgarten in the canton of Aargau in Switzerland. In January 2010 Hilfikon merged with the neighbour village of Villmergen.

Hilfikon was first mentioned in 924 as Hilfiniswilare, in1250 as Hilfinchon. Other variants of the name e.g. Hilffickonn can found in many old documents. In 1290 Markwart and Arnold von Hilfikon, ministerials of the Habsburgians, built a tower house in Hilfikon and ruled the village.

Lucerne conquered Hilfikon and the nearby villages of Büttikon, Sarmenstorf, Uezwil and Villmergen in 1415, but returned them in 1425 to the joint rule of the Swiss Confederates. Hilfikon thereafter belonged to the Villmergen district in the Freie Ämter, a common subject territory.

Part of the First Battle of Villmergen (1656) took place on Hilfikon territory and caused hundreds of deaths. Before the Second Battle of Villmergen (1712), the castle served as headquarters for Catholic troops. A later peace settlement granted rule in the lower Freie Ämter, including Hilfikon, exclusively to the Reformed cantons of Bern, Zurich and Glarus. After the French invasion of 1798 and the creation of the Helvetic Republic, Hilfikon and Büttikon formed an administrative unit in the short-lived Canton of Baden. When the Canton Aargau was founded in 1803, Hilfikon became autonomous again.

In the 19th century the Canton Aargau refurbished the main road through the village. Residents lived mainly from agriculture, crafts, and home-based straw weaving. A water reservoir was built in 1904 and electricity arrived in 1905. The Wohlen–Meisterschwanden railway, opened in 1916 with a stop at Hilfikon, connected the village to the Swiss train network. The railway was closed in 1997 and public transport was picked-up by a public bus service.

Population growth remained modest, preserving Hilfikon’s rural character. After local approval votes in 2007, Hilfikon merged with Villmergen on 1 January 2010 and ceased to exist as an independent municipality.

Ecclesiastically, Hilfikon always belonged to Villmergen parish. A castle chapel built in 1510 was used for local services; the municipality bought it in 1832 and transferred it to a private chapel association in 1947. In 1750 Franz Viktor Augustin von Roll took the old chapel down, replacing it with the present elongated chapel built by master mason Johann Marti. The new chapel's choir houses a replica of the Church of the Holy Sepulchre. The chapel has a gabled roof, a polygonal choir, and stands at the western corner of the castle above a steep slope. A six-sided roof turret with a pointed spire rises above the choir ridge. A square sacristy with a lean-to roof is attached on the southeast side where the nave meets the choir. The interior is in Rococo style. Wall and ceiling paintings by Franz Anton Rebsamen were whitewashed in 1901, then partly uncovered during restorations in 1954–55 and 1959–60. The altar features an elaborately carved tabernacle and a life-size Crucifixion by Johann Baptist Babel. A wooden Louis XVI–style pulpit was added around 1800 in front of the choir arch. The restored frescoes and the full-scale replica of the Holy Sepulchre of Jerusalem are considered important cultural treasures.

The castle of Hilfikon was built on the premises of the tower house of Markwaldus and Arnoldus de Hilfikon. Little is known about the ownership between 1290 and 1472, the first mention and when it was owned by Bertold VII Schwend of Zurich respectively. In 1498 it became a fief of Hans von Seengen, and in 1506–10 it was owned by Melchior von Gilgen of Lucerne. He also purchased the Bailiwick of Sarmenstorf in 1514, and in 1510 donated a chapel. In 1628 the property was purchased by John Lussi Landamman for Unterwalden, then in 1644 it went to the Zwyer family of Evibach in Silenen. In 1743 the village transferred by marriage to the Tschudi family of Glarus, which were deposed in 1749 by Augustin Victor Franz Roll from Solothurn and remained in the family's possession for almost 100 years.