The 2019 Estoril Open (also known as the Millennium Estoril Open for sponsorship purposes) was a professional men's tennis tournament played on outdoor clay courts. It was the fifth edition of the Estoril Open, and part of the ATP Tour 250 series of the 2019 ATP Tour. The event took place at the Clube de Ténis do Estoril in Cascais, Portugal, from April 29 through May 5, 2019.[1]
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Stefanos Tsitsipas | 8 | 1 | ||
 Italy | ||||
 France | Gaël Monfils | 19 | 3 | |
 Belgium | David Goffin | 22 | 4 | |
 Serbia | Dušan Lajović | 24 | 5 | |
 Australia | Alex de Minaur | 26 | 6 | |
 Spain | Pablo Carreño Busta | 29 | 7 | |
| Frances Tiafoe | 30 | 8 |
The following players received wildcards into the singles main draw:
The following player received entry as a special exempt:
The following players received entry from the qualifying draw:
The following players received entry as lucky losers:
Hugo Dellien Filip Krajinović → replaced by Pablo Cuevas Fabio Fognini → replaced by Filippo Baldi Jaume Munar → replaced by Nicolás Jarry
Cameron Norrie → replaced by 
Guido Andreozzi| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
| Rajeev Ram | United Kingdom | Joe Salisbury | 41 | 1 | ||
 Japan | Ben McLachlan | Matwé Middelkoop | 69 | 2 | ||
| Argentina | Leonardo Mayer | João Sousa | 90 | 3 | ||
 New Zealand | Marcus Daniell | Wesley Koolhof | 95 | 4 |
The following pairs received wildcards into the doubles main draw:
The following pairs received entry as alternates:
John Millman (Left foot injury)
Reilly Opelka (Back pain)See main article: 2019 Estoril Open – Singles.
See main article: 2019 Estoril Open – Doubles.
Jérémy Chardy / Fabrice Martin def. Luke Bambridge / Jonny O'Mara, 7–5, 7–6(7–3)