|Date of birth||10 February 1993|
|Place of birth||Třinec, Czech Republic|
|Height||1.85 m (6 ft 1 in)|
|Playing position||Central Midfielder|
|2009–2010||Czech Republic U17||14||(5)|
|2011–2013||Czech Republic U19||11||(1)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 2 September 2012.
† Appearances (Goals).
Twardzik was born in Czech Republic but educated in Germany as his father played football there. Twardzik and twin brother Patrik started off their careers with Sachsen Leipzig before being signed by Hertha Berlin. On 1 February 2009, they were both signed by Celtic, a week before their 16th birthday. Filip and Patrik both suspended their education when they moved to Celtic. Their mother also moved to Scotland to help them adjust to their new life.
Twardzik made his first-team debut for Celtic on 8 January 2012, coming on as a 70th minutes substitute in a Scottish Cup win against Peterhead. He made his second appearance in the next round of the Scottish Cup against Inverness. Coming on as a late substitute in the 93rd minute. His league debut came on 7 April in a 6–0 against victory Kilmarnock, he came on shortly after the start of the second half and assisted the fifth goal with a clever back-heel.
He played three times in the 2010 UEFA European Under-17 Football Championship. He played 14 times in total for Czech Republic U17s scoring five goals. He made his competitive debut for Czech Republic U19s on 21 May 2011, in a 1–0 victory over Netherlands.
- "Filip Twardzik career stats". Uefa. Retrieved 21 December 2010.
- "Czech display gives Twardzik hope". Uefa.com. 22 May 2010. Retrieved 11 August 2011.
- "Czech siblings Filip & Patrik Twardzik hoping to emulate McStay brothers at Celtic". Daily Record. 11 December 2009. Retrieved 10 August 2011.
- "Czech twins lured". Scotsman. 3 February 2009. Retrieved 10 August 2011.
- "Peterhead 0–3 Celtic". BBC Sport. 8 January 2012. Retrieved 9 January 2012.
- "Inverness Caledonian Thistle v Celtic Match facts". http://www.guardian.co.uk/football/match/2012/feb/04/invernesscaledonianthistle-v-celtic. 4 February 2012. Retrieved 8 April 2012.
- "Scottish Premier League – Live". BBC Sport. 7 April 2012. Retrieved 8 April 2012.
- "How Celtic won the title". STV.tv. 7 April 2012. Retrieved 8 April 2012.
- Filip Twardzik international stats at the Football Association of the Czech Republic website (Czech)