A kauppala was a compromise by design: town-like in function, but without the full rights and obligations the old chartered cities carried. Ikaalinen's version was more compromised than most. The rural municipality collected the taxes of the market town's residents and then handed back substantial annual grants for roads, water and drains, an arrangement that made the arithmetic work and self-respect rather harder. Market-town residents held the vote in both councils, which meant they voted twice and governed once.

In 1972 the whole municipality was folded together into a single independent kauppala, which promptly adopted the old rural parish's coat of arms as its own. Five years later the Finnish state abolished the category altogether, and every surviving market town in the country became a city on the first day of 1977. Ikaalinen had been first in through the door. It went out with everybody else.

Ikaalinen had been a chapel of Hämeenkyrö for well over a century when, in 1641, the regency governing on behalf of the child queen Christina cut it loose as a parish in its own right. It came into the world enormous. The new parish took in what are now Jämijärvi, Kankaanpää, Karvia, Kihniö, Parkano and Honkajoki — a stretch of western Finland that has since split into six separate municipalities, the last of them Jämijärvi, which left in 1908.

The centre sits on a peninsula pushing out into Kyrösjärvi. A medieval church gave way to a second in the 1640s and then to the present one, built between 1799 and 1801, when parishioners still rowed to services in long church boats. Along the southern edge runs Hämeenkangas, the esker chain that carried the old Kyrönkankaantie road from Häme up to Ostrobothnia. Until the 1990s all of this counted as Satakunta rather than Pirkanmaa.

The spa began as one man's good idea. In 1884 a merchant named Gustaf Nestor Eränen, impressed by what Naantali had made of sea-bathing, put up a bath house beside the bridge to Toivolansaari. Everyone called it Eränen's sauna; by 1896, with the market town bought in as part-owner, the documents call it the market town's sauna. The present building dates from 1990 and ranks among the largest multi-purpose spas in the Nordic countries.

The town's other great draw was considerably louder. Sata-Häme Soi, started in 1972 by Heikki Eränen, rector of the local civic college, grew under its first artistic director Lasse Pihlajamaa into the biggest accordion festival in Finland. Its Golden and Silver Accordion competitions settled national reputations. In 2007 it pulled more than thirty thousand people into a town of seven thousand. Then a funding quarrel, two cancelled pandemic summers and accumulated debt finished it off. The last Sata-Häme Soi was held in June 2023, and the association filed for bankruptcy that September.

Bertel Strömmer was born here on 11 July 1890, son of the Ikaalinen pharmacist. He qualified as an architect in 1913 and served as city architect of Tampere from 1918 to 1953 — thirty-five years and well over a hundred and fifty buildings, most of them in that city. Hotel Tammer is his, and the bus station. So are Ikaalinen's own town plans of 1917 and 1942, and the pharmacy building that later became its town hall. So, too, was Saavutus, the villa he designed for a schoolmate from his Tampere lyceum days: F. E. Sillanpää of Hämeenkyrö, the parish Ikaalinen had walked out of in 1641.

Edvard Gylling's road ran the other way. Born in Kuopio in 1881, raised on his family's Kalmaa estate here, married in 1906 to the daughter of the Ikaalinen district doctor, he became a statistician, a Social Democratic member of parliament, and then, after the Civil War drove him east, head of government in Soviet Karelia from 1920 to 1935. For fifteen years he built a Finnish-speaking republic inside the Soviet Union and believed it would hold. He was arrested in Stalin's purges and shot at Kommunarka on 14 June 1938.

Krista Pärmäkoski was born in Ikaalinen on 12 December 1990 and never left her home club. Racing for Ikaalisten Urheilijat, she has taken twelve medals at Olympic and world championship level, including a silver and two bronzes at Pyeongchang in 2018.

The northern edge of the municipality reaches into Seitseminen National Park, founded in 1982 across 45.5 square kilometres of bog, esker and old forest. Its emblem is the marten. At Multiharju, protected as early as 1910, the oldest pines are approaching four hundred years.

The population has been sliding since 1980 — 8,137 then, 6,704 at the end of 2025, the ordinary arithmetic of small-town Finland. Ikaalinen's answer to that arithmetic is at least distinctive. Since 2010 it has hosted Puistofilosofia in the central park: several days of philosophy, argued in public, out of doors.