Hlaváčková married former Italian tennis player and WTA employee, Fabrizio Sestini, in July 2017.

[9] Hlaváčková won her first International Tennis Federation (ITF) doubles title in 2003, on 19 October, with compatriot Tereza Szafnerová.

In May 2006, Hlaváčková won her first ITF singles title at a 25k in Tenerife, Spain, when she beat Monique Adamczak in the final.

Hlaváčková and Sandra Klösel of Germany entered the 2007 Wimbledon women's doubles competition main draw as lucky losers.

The team defeated Klaudia Jans and Alicja Rosolska in the first round, but fell to Michaëlla Krajicek and Agnieszka Radwańska in the second.

Hlaváčková won her fourth title with Lucie Hradecká in Jersey, Great Britain to retain her crown.

She made a successful WTA Tour partnership with Lucie Hradecká, and teamed with her to win the 2008 ECM Prague Open in their home country.

[11] She won three 25k singles titles in 2010: in Sutton, England in February, in Les Contamines-Montjoie, France in July and in Vigo, Spain in August.

[11] Hlaváčková won her first Grand Slam title in doubles with Hradecká at the 2011 French Open, beating Sania Mirza and Elena Vesnina in the final.

[11] On 13 August 2016, at the Rio Summer Olympics, Hlaváčková's left eye was hit by a ball, from an overhead volley from Martina Hingis.