Millwall's first-ever opponents in European football will be Hungarian outfit Ferencvaros.
Millwall chairman Theo Paphitis is relishing his side's European debut
The Lions will play Ferencvaros in the Uefa Cup first round, which sees Rangers playing Maritimo of Portugal.
Newcastle play Israeli outfit Hapoel Sakhnin, and Middlesbrough will meet Banik Ostrava of the Czech Republic.
Hearts will play SC Braga from Portugal while Shelbourne meet Lille of France, with the two-legged ties to be played on 16 and 30 September.
The Uefa Cup ties will be Millwall and Middlesbrough's first adventures in European football.
Championship outfit Millwall qualified due to reaching last season's FA Cup final while Middlesbrough got their place after winning the Carling Cup.
Millwall assistant boss Ray Wilkins told BBC London he thinks the Lions could have had a much kinder draw.
"They are one of the top teams in Hungarian football and have a fantastic history, so we probably have to face the hardest side," said Wilkins.
"But it's a great adventure for us and we will give it our best shot."
Chairman Theo Paphitis added: "Hopefully we will get a capacity crowd at home for an unforgettable night of European football at the Den."
Middlesbrough manager Steve McClaren is expecting a tough two legs against Czech champions Banik Ostrava.
He said: "They are always tough games in Europe, we weren't expecting an easy draw and Banik have proven pedigree.
"Only good teams win their league, whatever the country, and they beat Bayer Leverkusen at home in a Champions League match, so they will be tough.
"I know many of our fans won't know their name but they will be dangerous and we are expecting a tough game."
Newcastle boss Sir Bobby Robson says his team will take nothing for granted when they take on Hapoel Sakhnin.
"We will treat them with respect as we do all our opponents, though we know very little about them," said Robson.
"We expect they know more about us due to the popularity of the Premiership on television around Europe.
"We will scout them thoroughly, take no chances and be fully prepared for the first leg. It's ground-breaking as we have never played in Israel before."
SPL giants Rangers will be disappointed to find themselves in Europe's secondary club competition, having been knocked out of the Champions League at the qualifying stage by CSKA Moscow.
The Gers' first opponents in the Uefa Cup are Maritimo, with the first leg at Ibrox.
And Hearts will make their competitive debut at Murrayfield Stadium against another Portuguese side, Sporting Club de Braga.
Graz AK (Austria) v Litex Lovech (Bulgaria)
Lazio (Italy) v Metalurg Donetsk (Ukraine)
Bodo/Glimt (Norway) v Besiktas (Turkey)
Shelbourne (Ireland) v Lille (France)
HEARTS v Braga (Portugal)
Austria Vienna (Austria) v Legia Warsaw (Poland)
Banska Bystrica (Slovakia) v Benfica (Portugal)
Partizan Belgrade (Serbia & M) v Dinamo Bucharest (Romania)
Parma (Italy) v Maribor (Slovenia)
Real Zaragoza (Spain) v Sigma Olomouc (Czech Republic)
Sporting (Portugal) v Rapid Vienna (Austria)
NEWCASTLE v Hapoel Bnei Sakhnin (Israel)
Steaua Bucharest (Romania) v CSKA Sofia (Bulgaria)
Wisla Krakow (Poland) v Dinamo Tbilisi (Georgia)
Utrecht (Netherlands) v Djurgarden (Sweden)
MILLWALL v Ferencvaros (Hungary)
Schalke 04 (Germany) v Liepajas Metalurg (Latvia)
Maccabi Haifa (Israel) v Dnipro Dnipropetrovsk (Ukraine)
Terek Grozny (Russia) v Basel (Switzerland)
Odd Grenland (Norway) v Feyenoord (Netherlands)
Aab Aalborg (Denmark) v AJ Auxerre (France)
Sevilla (Spain) v Nacional Madeira (Portugal)
Nova Gorica (Slovenia) v AEK Athens (Greece)
Standard Liege (Belgium) v VfL Bochum (Germany)
Red Star Belgrade (Serbia & M) v Zenit St Petersburg (Russia)
Trabzonspor (Turkey) v Athletic Bilbao (Spain)
Ujpest (Hungary) v VfB Stuttgart (Germany)
Maccabi Petah Tikva (Israel) v Heerenveen (Netherlands)
Panionios (Greece) v Udinese (Italy)
Levski Sofia (Bulgaria) v Beveren (Belgium)
Dinamo Zagreb (Croatia) v Elfsborg (Sweden)
Hafnarfjordur (Iceland) v Alemannia Aachen (Germany)
MIDDLESBROUGH v Banik Ostrava (Czech Republic)
Club Bruges (Belgium) v Chateauroux (France)
PAOK Salonika (Greece) v AZ Alkmaar (Netherlands)
Ventspils (Latvia) v Amica Wronki (Poland)
Sochaux (France) v Stabaek (Norway)
Egaleo (Greece) v Genclerbirligi (Turkey)
RANGERS (Scotland) v Maritimo (Portugal)
Villarreal (Spain) v Hammarby (Sweden)
First leg ties to be played on 16 September, second leg ties to be played on 30 September.