Yes, there are garlic mustard lookalikes, but it depends on the current form of the plant. 

In its low-growing rosette form, garlic mustard looks like these common plants:

• fringecup (Tellima grandiflora) – look for hairy leaves and stems
• piggy-back plant, (Tolmiea menziesii) – look for hairy leaves and stems
• ground ivy (Glecoma hederacea) - leaves are similar, but creeps along the ground (roots on the stem nodes 

In its flowering form, garlic mustard is often confused with:

• hairy bittercress, (Cardamine hirsuta) – look for short plants, 6 to 8-inches high, and compound or deeply-lobed leaves, flowering in March 

In its mature form with ripe seedpods, garlic mustard looks like many mustard cousins, including:

• black mustard, (Brassica nigra) – look for longer pods with very pronounced seedbumps

 Photos:  fringecup (L) with garlic mustard rosette (R); and bittercress (L) with nipplewort (R)