PETRO POROSHENKO Poroshenko, the incumbent, came to power in 2014 with the image of a "good oligarch." The bulk of his fortune came from a seemingly innocuous source, the chocolate-maker Roshen, hence his nickname "The Chocolate King."
He promised to divest himself of the whole business upon becoming president. Five years later, there's little sweetness left in his image. He hasn't sold the chocolate business. Critics denounce him for having done little to combat Ukraine's endemic corruption, the war with Russia-backed separatists in the east grinds on with no clear strategy for ending it and while his economic reforms may have pleased international lenders, they've left millions of Ukrainians wondering if they can find the money to pay their utilities bills.
But the 53-year-old Poroshenko also has scored some significant goals for Ukraine's national identity and its desire to move out of Russia's influence. He signed an association agreement with the European Union — which predecessor Viktor Yanukovych turned away from, setting off the protests that eventually drove him out of office. Ukrainians now can travel visa-free to the European Union, a significant perk. He pushed relentlessly for the Ukrainian Orthodox Church to be recognized as self-standing rather than just a branch of the Russian church.
YULIA TYMOSHENKO Tymoshenko has abandoned the elaborate blond hair braid that made her the most recognizable figure of the 2004 Orange Revolution protests, but she's retained the vivid rhetoric and populist leanings.
In her third run for the presidency, the 58-year-old Tymoshenko is playing heavily to the economic distress of millions of Ukrainians. She has promised to reduce prices for household gas by 50 percent within a month of taking office, calling the price hikes introduced by Poroshenko to satisfy international lenders "economic genocide." She also promises to take away constitutional immunity for the president, the judiciary and lawmakers.
Before entering politics, Tymoshenko was widely called "the Gas Princess" because she headed a middleman company that imported Russian gas. Her popularity soared after the 2004 revolution and she was named prime minister. But her star soon fell again as she and President Viktor Yushchenko quarreled, and he dismissed her after nine months in office. She returned to the premiership in 2007 and lasted until 2010, when she lost the presidential election to Yanukovych.
In 2011, she was arrested and charged with abusing power as premier in a natural gas deal with Russia. Tymoshenko said the proceedings were politically motivated revenge, and Western governments voiced concern about her incarceration. She was released amid the disorder of the 2014 overthrow of Yanukovych, and lost a presidential election to Poroshenko three months later.
VOLODYMYR ZELENSKIY Zelenskiy may be approaching the point where life imitates art. The 41-year-old comic actor's most famous role is his TV portrayal of a schoolteacher who becomes president after a video of him denouncing corruption goes viral. Even before he announced his candidacy, Zelenskiy's name was turning up high in pre-election public opinion polls, with potential voters seemingly encouraged by his "Servant of the People" TV series (which became the name of his party).
Like his TV character, Zelenskiy the candidate has focused strongly on corruption. He proposes a lifetime ban on holding public office for anyone convicted of corruption and calls for a tax amnesty under which someone holding hidden assets would declare them, be taxed at 5 percent and face no other measures.
He supports Ukraine's eventual membership in NATO, but only if the country were to approve this in a referendum. Zelenskiy's clean image has been shadowed by his admission that he had commercial interests in Russia through a holding company and by persistent speculation about links with oligarch Ihor Kolomoisky, who owns the television station that airs "Servant of the People."