|Full name||Marios Siampanis|
|Date of birth||28 September 1999|
|Place of birth||Katerini, Greece|
|Height||1.88 m (6 ft 2 in)|
(on loan from Olympiacos)
|2019–||→ Nottingham Forest (loan)||0||(0)|
* Senior club appearances and goals counted for the domestic league only and correct as of 15 March 2018|
‡ National team caps and goals correct as of 21 March 2018
On April 14, 2015 it was announced that Siampanis signed a professional contract with PAOK and started training with the first team. On February 10, 2017 Siampanis extended his contract with PAOK until 2019. According to reports, teenage goalkeeping prospect, Siampanis, could be on his way out of the club despite PAOK officials wanting to keep the talented shot-stopper. Having been at the club since he was just 16 years of age, the youngster has only made two appearances in the senior team and may look for greater opportunities elsewhere.
On 1 July 2019, the 19-year-old international never received a chance with the PAOK senior team, and with his contract expiring this summer, the talented goalkeeper took the decision to leave the club and pen a four years' deal with Athenian giants Olympiacos for an undisclosed fee.  On 11 August 2019, he joined English Championship club Nottingham Forest on a season-long loan deal from Olympiacos. 
- "Ο 16χρονος Σιαμπάνης που κλέβει τις εντυπώσεις..." (in Greek). www.sdna.gr. 14 April 2015. Retrieved 4 February 2017.
- "Pouggouras and Siampanis at PAOK until 2019". www.paokfc.gr. 10 February 2017. Retrieved 11 February 2017.
- "Επίσημο: Ο Σιαμπάνης στον Ολυμπιακό" (in Greek). www.fosonline.gr. 1 July 2019.
- "Ανακοίνωσε τη μεταγραφή του στην Νότιγχαμ ο Σιαμπάνης" (in Greek). www.sdna.gr. 11 August 2019. Retrieved 15 August 2019.
- "Ελλάδα - Ρωσία (U19) 2-1: Μεγάλη πρόκριση με ανατροπή για Έλληνες διεθνείς". www.protothema.gr. 14 November 2017.