2018 Open Harmonie mutuelle

{{Infobox tennis event|2018|Open Harmonie mutuelle|

| date=26 March – 1 April

| edition=15th

| draw=32S / 16D

| surface=Hard

| location=Saint-Brieuc, France

| champs={{flagicon|LTU}} Ričardas Berankis

| champd={{flagicon|NED}} Sander Arends / {{flagicon|AUT}} Tristan-Samuel Weissborn

}}

The 2018 Open Harmonie mutuelle was a professional tennis tournament played on hard courts. It was the fifteenth edition of the tournament which was part of the 2018 ATP Challenger Tour. It took place in Saint-Brieuc, France between 26 March and 1 April 2018.

Singles main-draw entrants

=Seeds=

class="sortable wikitable"
width="70"| Country

! width="175"| Player

! Rank1

! Seed

{{flag|CYP}}

|Marcos Baghdatis

|82

|1

{{flag|LTU}}

|Ričardas Berankis

|103

|2

{{flag|SVK}}

|Lukáš Lacko

|104

|3

{{flag|UKR}}

|Sergiy Stakhovsky

|118

|4

{{flag|GER}}

|Oscar Otte

|129

|5

{{flag|SWE}}

|Elias Ymer

|133

|6

{{flag|FRA}}

|Corentin Moutet

|138

|7

{{flag|EST}}

|Jürgen Zopp

|147

|8

  • Rankings are as of 19 March 2018.

=Other entrants=

The following players received wildcards into the singles main draw:

The following players received entry into the singles main draw as special exempts:

The following players received entry from the qualifying draw:

Champions

=Singles=

{{main|2018 Open Harmonie mutuelle – Singles}}

=Doubles=

{{main|2018 Open Harmonie mutuelle – Doubles}}