Tim McGraw's little bro was at Nashville Film Fest Monday night. Tim McGraw's half-brother, Mark McGraw -- also the son of late legendary Phillies pitcher Tug McGraw - is an actor, and was in a movie tonight called No Boundaries. Tim and wife Faith Hill were there in support of Mark's work.
No Boundaries description from the film festival:
Isabel Moreno crosses the border into the United States, thinking only of raising enough money to save her deathly ill mother. In Philadelphia, she finds comfort in her cousin Martin and is embraced by his neighbors, Gloria and Maurice. She is surprised to find a new family far from home, but even more surprised to fall in love with the one man that could put her right back where she started, Christopher Fox (McGraw), an immigration agent. Faced with an ultimatum, Isabel is forced to question her loyalties and choose between her freedom and the love of her life.

This photo of the brothers together is from 2005.

Name:	Tim McGraw
Birth Name:	Samuel Timothy McGraw
Height:	6'
Sex:	M
Nationality:	American
Birth Date:	May 1, 1967
Birth Place:	Delhi, Louisiana, USA
Profession:	Actor, Country Singer
Education:	Northeast Louisiana University (dropped out in 1989 to pursue musical career)
Husband/Wife:	Faith Hill (musician; born on September 21, 1967; married on October 6, 1996, in Rayville, Louisiana)
Father:	Tug McGraw (Major League Baseball relief pitcher; born on August 30, 1944; died on January 5, 2004 because of brain cancer)
Mother:	Elizabeth Trimble (nee D'Agostino; was a waitress)
Half Sister:	Cari Lynn Velardo (mother: Phyllis Kline)
Half Brother:	Mark McGraw (actor; mother: Phyllis Kline), Matthew McGraw (mother: Diane)
Step Father:	Horace Smith
Daughter:	Audrey Caroline McGraw (born on December 6, 2001 at 4:39 p.m. in Nashville; father: Tim McGraw), Maggie Elizabeth (born on August 12, 1998; father: Tim McGraw ), Gracie Katherine (born on May 5, 1997; father: Tim McGraw)
Claim to fame:	His second album 'Not a Moment Too Soon' with hit single 'Indian Outlaw' in 1994